using animals for medical research cons

14 Pros and Cons of Animal Research

Animal research is the process of using non-human animals to control variables that may affect biological systems or behaviors in experiments. It is the process of animal testing that is done under the guise of research to benefit humanity, but the applied research may have little or no concern to the animals involved.

Up to 100 million animals, from fish to chimpanzees, may be used every year for the purpose of animal research. Reptiles, amphibians, fish, rats, and mice make up about 85% of the testing population in any given year.

The advantage of animal research is that it puts no human lives at risk. Experiments can take place to determine if a product or idea will work as intended. If it does, then it can be tested on humans with a lower risk of a negative outcome.

The disadvantage of animal research is that it lessens the value of life. Most animals, once the testing process has been completed, are euthanized. Many of those animals are purposely bred for the experiments being performed as well, which means millions of animals are at a higher risk of suffering from abuse or neglect in a field that is often poorly regulated.

Here are some of the additional pros and cons of animal research to discuss.

What Are the Pros of Animal Research?

1. It has led to several medical advancements for humans. The British Royal Society has released a statement regarding animal research, noting that almost every 20th century medical achievement relied on the use of animals in some way during the development process. Because it cannot be fully replaced by computer simulations or models, the argument is that live testing will continue to be needed.

2. It enhances the safety of the products being released. Animal testing helps to lessen the risk of an unplanned event occurring when humans use or ingest the products that are part of the animal testing experiment. Drugs can be potentially and immediately harmful to humans, especially during the testing phase of a product, so animal testing allows for researchers to determine the quality and safety of a product before humans take it.

3. There are no other testing alternatives. Animals are the closest thing to humans on our planet. If one assumes that human life is more valuable than animal life, then performing experiments on animals makes sense because it offers the chance to explore how the various living systems within a body may react when exposed to a test sample. Animals and humans share numerous systems, including the central nervous system, and the data collected can be used to improve products.

4. Some animals are almost carbon copies of humans. The reason why mice are frequently used in animal research is that their genetic profile is 98% similar to humans. Chimpanzees were popular to use in the past, and still are in some areas of the world, because their genetic profile is 99% similar to a human. With similar organs, circulatory systems, and reactions to an illness, researchers can look at how animals react and be able to make comfortable prediction about how humans might react.

5. It offers a different set of legalities. Testing humans with invasive experiments could result in death. Although there will always be a risk when testing new items, even after animal research has provided positive data, the risks to a human without animal research would be incredibly high. Through animal research, the legality of accidentally causing the death of an animal is very different than what would occur with the accidental death of a human.

6. It provides an opportunity to examine a complete life cycle. In many countries, the average life expectancy of a human exceeds 70 years of age. Some nations have an average life expectancy of over 80 years. In comparison, a mouse has a lifespan of 2-3 years, allowing researchers the opportunity to study through research and experimentation how something may affect the life cycle. Any long-term research involves mice and rats because of this unique aspect to the research.

7. There are protections in place for the animals. Although animal research may have ethical concerns, the US has regulated its practice since 1966. Veterinarians are required to inspect the living conditions of the animals. Committees must approve animal research and be held responsible for the humane treatment of each animal. Access to food and water is mandatory, as are shelters that follow minimum sizing standards.

What Are the Cons of Animal Research?

1. Many of the items that are tested are never used. Animal testing may provide safety benefits for new products, but some of the items that are tested will never be used. That means animals will likely be sacrificing their lives to determine the safety of a product that a human will never even know was being developed. With no direct societal benefit produced, what is the benefit of an animal suffering from the testing process?

2. It can be an expensive practice. Caring for an animal requires a large investment. Some of the animals that are used for testing are bought at auction or taken from the wild, which brings additional costs into the process. According to Petfinder, the total cost of caring for a single dog could be over $9,000 per year. Even at the low end of the scale, the car cost is over $500. Now multiple those costs over an entire laboratory and the cost of animal research becomes very high, very quickly.

3. It may not offer valid results. The structure of an animal’s body is very different from the structure of a human’s body. That means animal research can be more unreliable than even researchers claim it may be. Several drugs have passed animal testing, but have been found to be harmful to humans. In 2004, the FDA estimated that 92% of drugs that pass their pre-clinical tests, including animal research, fail to reach the market. Recent data suggests that failure rates from animal research to human research could be even higher, at 96%, according to the NIH. Nearly 100 vaccines for HIV showed potential in primates, but failed in humans. That means the results that animal research can produce may not even be valid.

4. Many facilities are exempt from animal welfare laws. About 4% of the animals that are involved in ongoing research projects are covered by animal welfare laws. That means there are more than 20 million animals who could be at a high risk of abuse or neglect in the name of research. Even when the facilities are in compliance with the law, they are governed by committees that are self-appointed and only a direct inspection of the facility would let someone know there are issues going on.

5. Animals don’t need to be the “only” method of research. Although testing living tissues will be beneficial compared to computer simulations for the recent future, there are methods of research that can involve living tissues that don’t put the lives of animals at risk. From living cell lines to cultures and other forms of cell harvesting, there are possibilities available. A cell line from cervical cancer cells taken in 1951 is still being researched, even though the individual died from that cancer in the same year.

6. Poor research practices invalidate the data obtained. Data discrepancies are not the only issue that face animal research transitioning to human research. When poor research practices are used, the data that is obtained could be invalidated. There is also the possibility that poor research practices could create false positive data that could then place human lives at risk. Unless there is accurate and complete oversight over the current field of animal research, this threat to the data will always exist.

7. Reverse data can also be a problem with animal research. There are drugs and products that could be harmful to animals, but highly beneficial to humans, and the current state of research priority would make it extremely difficult to know if this was the case. Animal testing occurs before human testing. An example of this issue is aspirin. It is a dangerous product for animals to have, but think of the millions of lives that have been improved or saved because of the drug. Insulin causes animal birth defects, but it saves lives every day. That is the reality of animal research.

The pros and cons of animal research will always be controversial. Testing animals to see if a product is safe may be better than testing humans first, but that also means the life of an animal is devalued. On the other hand, more animals are butchered for food every year than are used in animal experimentation, so the ethics of life value are more of a gray area than distinctly black and white.

How do you feel about the process of animal research?

Ethical care for research animals

WHY ANIMAL RESEARCH?

The use of animals in some forms of biomedical research remains essential to the discovery of the causes, diagnoses, and treatment of disease and suffering in humans and in animals., stanford shares the public's concern for laboratory research animals..

Many people have questions about animal testing ethics and the animal testing debate. We take our responsibility for the ethical treatment of animals in medical research very seriously. At Stanford, we emphasize that the humane care of laboratory animals is essential, both ethically and scientifically.  Poor animal care is not good science. If animals are not well-treated, the science and knowledge they produce is not trustworthy and cannot be replicated, an important hallmark of the scientific method .

There are several reasons why the use of animals is critical for biomedical research: 

••  Animals are biologically very similar to humans. In fact, mice share more than 98% DNA with us!

••  Animals are susceptible to many of the same health problems as humans – cancer, diabetes, heart disease, etc.

••  With a shorter life cycle than humans, animal models can be studied throughout their whole life span and across several generations, a critical element in understanding how a disease processes and how it interacts with a whole, living biological system.

The ethics of animal experimentation

Nothing so far has been discovered that can be a substitute for the complex functions of a living, breathing, whole-organ system with pulmonary and circulatory structures like those in humans. Until such a discovery, animals must continue to play a critical role in helping researchers test potential new drugs and medical treatments for effectiveness and safety, and in identifying any undesired or dangerous side effects, such as infertility, birth defects, liver damage, toxicity, or cancer-causing potential.

U.S. federal laws require that non-human animal research occur to show the safety and efficacy of new treatments before any human research will be allowed to be conducted.  Not only do we humans benefit from this research and testing, but hundreds of drugs and treatments developed for human use are now routinely used in veterinary clinics as well, helping animals live longer, healthier lives.

It is important to stress that 95% of all animals necessary for biomedical research in the United States are rodents – rats and mice especially bred for laboratory use – and that animals are only one part of the larger process of biomedical research.

Our researchers are strong supporters of animal welfare and view their work with animals in biomedical research as a privilege.

Stanford researchers are obligated to ensure the well-being of all animals in their care..

Stanford researchers are obligated to ensure the well-being of animals in their care, in strict adherence to the highest standards, and in accordance with federal and state laws, regulatory guidelines, and humane principles. They are also obligated to continuously update their animal-care practices based on the newest information and findings in the fields of laboratory animal care and husbandry.  

Researchers requesting use of animal models at Stanford must have their research proposals reviewed by a federally mandated committee that includes two independent community members.  It is only with this committee’s approval that research can begin. We at Stanford are dedicated to refining, reducing, and replacing animals in research whenever possible, and to using alternative methods (cell and tissue cultures, computer simulations, etc.) instead of or before animal studies are ever conducted.

Organizations and Resources

There are many outreach and advocacy organizations in the field of biomedical research.

• Learn more about outreach and advocacy organizations

Stanford Discoveries

What are the benefits of using animals in research? Stanford researchers have made many important human and animal life-saving discoveries through their work. 

• Learn more about research discoveries at Stanford

• Alzheimer's disease & dementia
• Arthritis & Rheumatism
• Attention deficit disorders
• Autism spectrum disorders
• Biomedical technology
• Diseases, Conditions, Syndromes
• Endocrinology & Metabolism
• Gastroenterology
• Gerontology & Geriatrics
• Health informatics
• Inflammatory disorders
• Medical economics
• Medical research
• Medications
• Neuroscience
• Obstetrics & gynaecology
• Oncology & Cancer
• Ophthalmology
• Overweight & Obesity
• Parkinson's & Movement disorders
• Psychology & Psychiatry
• Radiology & Imaging
• Sleep disorders
• Sports medicine & Kinesiology
• Vaccination
• Breast cancer
• Cardiovascular disease
• Chronic obstructive pulmonary disease
• Colon cancer
• Coronary artery disease
• Heart attack
• Heart disease
• High blood pressure
• Kidney disease
• Lung cancer
• Multiple sclerosis
• Myocardial infarction
• Ovarian cancer
• Post traumatic stress disorder
• Rheumatoid arthritis
• Schizophrenia
• Skin cancer
• Type 2 diabetes
• Full List »

share this!

August 31, 2023

This article has been reviewed according to Science X's editorial process and policies . Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

trusted source

written by researcher(s)

We won't always have to use animals for medical research: Here's what we can do instead

by Greg Williams and Laura Anne Thomas, The Conversation

Animals have been used for medical research for thousands of years, dating back to ancient Greece where the first dissections were performed.

These days, one of the main uses of animals is to ensure the safety of medical products before they're trialed in humans.

But in addition to the important ethical reasons for minimizing animal use, the reality is sometimes animals just aren't that good at predicting human responses. No animal model, for example, has captured all the human characteristics of complex illnesses like Alzheimer's disease or chronic inflammatory demyelinating polyneuropathy (a neuromuscular disease). This makes is hard to develop effective treatments and cures.

Thankfully, researchers are making progress in developing a collection of alternative approaches, called "non-animal models." A new report from our team at CSIRO Futures examines the potential of non-animal models and the actions Australia will need to take to pursue their use.

What are non-animal models?

Non-animal models are an alternative set of models that use human cells, tissues and data.

These have the potential to better mimic human responses. In doing so, this can more accurately predict if a medical product is likely to fail, allowing reinvestment in products that are more likely to succeed.

Computer simulations or "in silico models" are one example. These can be used across the medical product development process to complement—and in time potentially replace—other model types. They can be used in drug studies to model a drug's behavior within the body, from cellular interactions to processes that involve multiple organs.

Complex three-dimensional biological models are also maturing quickly. Examples include:

organoids —organ "buds" that can be propagated from stem cells or taken from biopsies

organs-on-chips —cells cultured in a miniature engineered chip. These attempt to replicate the physical environment of human organs.

What can we use non-animal models for?

In theory, we can use non-animal models for everything we use animal models for—and more.

Simple non-animal models ( human cells cultured over a flat surface) are already used to help identify drug targets due to their ability to test a large number of compounds and experimental conditions.

In the future, non-animal models will reduce—and eventually replace—animal use across a range of applications:

• screening potential drugs to see how well they work
• toxicology (safety) testing
• helping to screen, select and stratify shortlisted participants for clinical trials. This might include an assessment of their unique response to a potential drug.
• using patient cells to identify the treatment most likely to help that individual.

Outside of medical products designed for humans, non-animal models can also support innovation in veterinary and agricultural medicines, cosmetic testing and eco-toxicology.

An export opportunity for Australia

Non-animal models present an economic opportunity for Australia, where the models, their components, and surrounding services could be exported to the world.

Our novel economic analysis sized the potential Australian market for two non-animal models: organoids and organs-on-chips. Other models were unable to be sized due to a lack of global market data.

We estimate the Australian organoid market could be worth A$1.3 billion annually by 2040 and create 4,200 new jobs.

The organs-on-chips market could be worth A$300 million annually by 2040 and create 1,000 new jobs. This estimate is lower as this technology is currently less advanced but holds the potential to grow significantly beyond 2040.

Several Australian entities are already contributing to these opportunities. The Murdoch Children's Research Institute, for example, provides stem cell and modeling expertise as part of reNEW , a €300 million international collaboration .

Another example is from Schott Minifab , an international biotech and medical device company with Australian roots, which has successfully established scaled production of non-animal model components in Australia for domestic and export markets.

Making it a reality

Non-animal models have already begun to complement and replace animal use in some areas, such as identifying drug targets.

However, accelerating their development and adoption across a wider range of applications will require further technical advances to lower cost and validate their performance as superior models.

Australia has several research strengths in this field but we need a concentrated effort to help our research make it through to real world impact.

Our report makes ten recommendations for supporting Australia's pursuit of these opportunities. Critical activities over the next five years include:

• coordinating local capabilities
• investing in upgraded infrastructure
• creating and collating data that compares animal and non- animal model performance.

Governments, industry and research must collaborate to deliver against these actions. Success will only come from collective efforts.

Explore further

Feedback to editors

Researchers find ethnic minorities are underrepresented in studies into multiple long-term health conditions

3 hours ago

Bacteria behind meningitis in babies explained

7 hours ago

Antibiotics reveal a new way to fight cancer

A urine-based test that detects tumor DNA fragments could offer early reliable screening for head and neck cancer

Multidisciplinary research team creates computational models to predict heart valve leakage in children

Research uncovers new reasons to target neutrophils for tuberculosis therapy

New treatment method using plasma irradiation promotes faster bone healing

8 hours ago

Good blood pressure control could prevent fibroids

9 hours ago

Study suggests the brain's reward system works to make others happy, not just ourselves

Researchers discover cause of rare congenital lung malformations

Related stories.

Lung organoids could replace animal testing and boost success in clinical trials

Apr 12, 2023

From a fish to a dish, how animal alternatives are advancing stroke research

Aug 4, 2023

Organ-on-a-chip models allow researchers to conduct studies closer to real-life conditions

Jan 11, 2023

FDA takes steps away from animal testing requirement

Aug 10, 2022

UK must not fall behind in race to 'humanize' drug discovery

Nov 16, 2018

Reproducing a retinal disease on a chip

Jun 15, 2017

Recommended for you

Mouse study finds small extracellular vesicles from young blood extend lifespan and restore physiological functions

10 hours ago

An effective drug delivery system for next-generation treatments to hitch a ride in cancer cells

Study on rats shows a junk food diet can cause long-term damage to adolescent brains

How AI improves physician and nurse collaboration to boost patient care

12 hours ago

Let us know if there is a problem with our content

Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form . For general feedback, use the public comments section below (please adhere to guidelines ).

Please select the most appropriate category to facilitate processing of your request

Thank you for taking time to provide your feedback to the editors.

Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.

E-mail the story

Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Medical Xpress in any form.

Newsletter sign up

Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we'll never share your details to third parties.

More information Privacy policy

Donate and enjoy an ad-free experience

We keep our content available to everyone. Consider supporting Science X's mission by getting a premium account.

E-mail newsletter

Research using animals: an overview

Around half the diseases in the world have no treatment. Understanding how the body works and how diseases progress, and finding cures, vaccines or treatments, can take many years of painstaking work using a wide range of research techniques. There is overwhelming scientific consensus worldwide that some research using animals is still essential for medical progress.

Animal research in the UK is strictly regulated. For more details on the regulations governing research using animals, go to the UK regulations page .

Why is animal research necessary?

There is overwhelming scientific consensus worldwide that some animals are still needed in order to make medical progress.

Where animals are used in research projects, they are used as part of a range of scientific techniques. These might include human trials, computer modelling, cell culture, statistical techniques, and others. Animals are only used for parts of research where no other techniques can deliver the answer.

A living body is an extraordinarily complex system. You cannot reproduce a beating heart in a test tube or a stroke on a computer. While we know a lot about how a living body works, there is an enormous amount we simply don’t know: the interaction between all the different parts of a living system, from molecules to cells to systems like respiration and circulation, is incredibly complex. Even if we knew how every element worked and interacted with every other element, which we are a long way from understanding, a computer hasn’t been invented that has the power to reproduce all of those complex interactions - while clearly you cannot reproduce them all in a test tube.

While humans are used extensively in Oxford research, there are some things which it is ethically unacceptable to use humans for. There are also variables which you can control in a mouse (like diet, housing, clean air, humidity, temperature, and genetic makeup) that you could not control in human subjects.

Is it morally right to use animals for research?

Most people believe that in order to achieve medical progress that will save and improve lives, perhaps millions of lives, limited and very strictly regulated animal use is justified. That belief is reflected in the law, which allows for animal research only under specific circumstances, and which sets out strict regulations on the use and care of animals. It is right that this continues to be something society discusses and debates, but there has to be an understanding that without animals we can only make very limited progress against diseases like cancer, heart attack, stroke, diabetes, and HIV.

It’s worth noting that animal research benefits animals too: more than half the drugs used by vets were developed originally for human medicine. 

Aren’t animals too different from humans to tell us anything useful?

No. Just by being very complex living, moving organisms they share a huge amount of similarities with humans. Humans and other animals have much more in common than they have differences. Mice share over 90% of their genes with humans. A mouse has the same organs as a human, in the same places, doing the same things. Most of their basic chemistry, cell structure and bodily organisation are the same as ours. Fish and tadpoles share enough characteristics with humans to make them very useful in research. Even flies and worms are used in research extensively and have led to research breakthroughs (though these species are not regulated by the Home Office and are not in the Biomedical Sciences Building).

What does research using animals actually involve?

The sorts of procedures research animals undergo vary, depending on the research. Breeding a genetically modified mouse counts as a procedure and this represents a large proportion of all procedures carried out. So does having an MRI (magnetic resonance imaging) scan, something which is painless and which humans undergo for health checks. In some circumstances, being trained to go through a maze or being trained at a computer game also counts as a procedure. Taking blood or receiving medication are minor procedures that many species of animal can be trained to do voluntarily for a food reward. Surgery accounts for only a small minority of procedures. All of these are examples of procedures that go on in Oxford's Biomedical Sciences Building. 

How many animals are used?

Figures for 2023 show numbers of animals that completed procedures, as declared to the Home Office using their five categories for the severity of the procedure.

# NHPs - Non Human Primates

Oxford also maintains breeding colonies to provide animals for use in experiments, reducing the need for unnecessary transportation of animals.

Figures for 2017 show numbers of animals bred for procedures that were killed or died without being used in procedures:

Why must primates be used?

Primates account for under half of one per cent (0.5%) of all animals housed in the Biomedical Sciences Building. They are only used where no other species can deliver the research answer, and we continually seek ways to replace primates with lower orders of animal, to reduce numbers used, and to refine their housing conditions and research procedures to maximise welfare.

However, there are elements of research that can only be carried out using primates because their brains are closer to human brains than mice or rats. They are used at Oxford in vital research into brain diseases like Alzheimer’s and Parkinson’s. Some are used in studies to develop vaccines for HIV and other major infections.

What is done to primates?

The primates at Oxford spend most of their time in their housing. They are housed in groups with access to play areas where they can groom, forage for food, climb and swing.

Primates at Oxford involved in neuroscience studies would typically spend a couple of hours a day doing behavioural work. This is sitting in front of a computer screen doing learning and memory games for food rewards. No suffering is involved and indeed many of the primates appear to find the games stimulating. They come into the transport cage that takes them to the computer room entirely voluntarily.

After some time (a period of months) demonstrating normal learning and memory through the games, a primate would have surgery to remove a very small amount of brain tissue under anaesthetic. A full course of painkillers is given under veterinary guidance in the same way as any human surgical procedure, and the animals are up and about again within hours, and back with their group within a day. The brain damage is minor and unnoticeable in normal behaviour: the animal interacts normally with its group and exhibits the usual natural behaviours. In order to find out about how a disease affects the brain it is not necessary to induce the equivalent of full-blown disease. Indeed, the more specific and minor the brain area affected, the more focussed and valuable the research findings are.

The primate goes back to behavioural testing with the computers and differences in performance, which become apparent through these carefully designed games, are monitored.

At the end of its life the animal is humanely killed and its brain is studied and compared directly with the brains of deceased human patients. 

Primates at Oxford involved in vaccine studies would simply have a vaccination and then have monthly blood samples taken.

How many primates does Oxford hold?

* From 2014 the Home Office changed the way in which animals/ procedures were counted. Figures up to and including 2013 were recorded when procedures began. Figures from 2014 are recorded when procedures end.

What’s the difference between ‘total held’ and ‘on procedure’?

Primates (macaques) at Oxford would typically spend a couple of hours a day doing behavioural work, sitting in front of a computer screen doing learning and memory games for food rewards. This is non-invasive and done voluntarily for food rewards and does not count as a procedure. After some time (a period of months) demonstrating normal learning and memory through the games, a primate would have surgery under anaesthetic to remove a very small amount of brain tissue. The primate quickly returns to behavioural testing with the computers, and differences in performance, which become apparent through these carefully designed puzzles, are monitored. A primate which has had this surgery is counted as ‘on procedure’. Both stages are essential for research into understanding brain function which is necessary to develop treatments for conditions including Alzheimer’s, Parkinson’s and schizophrenia.

Why has the overall number held gone down?

Numbers vary year on year depending on the research that is currently undertaken. In general, the University is committed to reducing, replacing and refining animal research.

You say primates account for under 0.5% of animals, so that means you have at least 16,000 animals in the Biomedical Sciences Building in total - is that right?

Numbers change daily so we cannot give a fixed figure, but it is in that order.

Aren’t there alternative research methods?

There are very many non-animal research methods, all of which are used at the University of Oxford and many of which were pioneered here. These include research using humans; computer models and simulations; cell cultures and other in vitro work; statistical modelling; and large-scale epidemiology. Every research project which uses animals will also use other research methods in addition. Wherever possible non-animal research methods are used. For many projects, of course, this will mean no animals are needed at all. For others, there will be an element of the research which is essential for medical progress and for which there is no alternative means of getting the relevant information.

How have humans benefited from research using animals?

As the Department of Health states, research on animals has contributed to almost every medical advance of the last century.

Without animal research, medicine as we know it today wouldn't exist. It has enabled us to find treatments for cancer, antibiotics for infections (which were developed in Oxford laboratories), vaccines to prevent some of the most deadly and debilitating viruses, and surgery for injuries, illnesses and deformities.

Life expectancy in this country has increased, on average, by almost three months for every year of the past century. Within the living memory of many people diseases such as polio, tuberculosis, leukaemia and diphtheria killed or crippled thousands every year. But now, doctors are able to prevent or treat many more diseases or carry out life-saving operations - all thanks to research which at some stage involved animals.

Each year, millions of people in the UK benefit from treatments that have been developed and tested on animals. Animals have been used for the development of blood transfusions, insulin for diabetes, anaesthetics, anticoagulants, antibiotics, heart and lung machines for open heart surgery, hip replacement surgery, transplantation, high blood pressure medication, replacement heart valves, chemotherapy for leukaemia and life support systems for premature babies. More than 50 million prescriptions are written annually for antibiotics. 

We may have used animals in the past to develop medical treatments, but are they really needed in the 21st century?

Yes. While we are committed to reducing, replacing and refining animal research as new techniques make it possible to reduce the number of animals needed, there is overwhelming scientific consensus worldwide that some research using animals is still essential for medical progress. It only forms one element of a whole research programme which will use a range of other techniques to find out whatever possible without animals. Animals would be used for a specific element of the research that cannot be conducted in any alternative way.

How will humans benefit in future?

The development of drugs and medical technologies that help to reduce suffering among humans and animals depends on the carefully regulated use of animals for research. In the 21st century scientists are continuing to work on treatments for cancer, stroke, heart disease, HIV, malaria, tuberculosis, diabetes, neurodegenerative diseases like Alzheimer's and Parkinson’s, and very many more diseases that cause suffering and death. Genetically modified mice play a crucial role in future medical progress as understanding of how genes are involved in illness is constantly increasing. 

• Academic Departments
• Centers, Institutes & Labs
• Faculty Directory
• Offices & Programs
• Patient Care
• Student Resources
• Faculty Resources

Can't find what you're looking for?

• Centers, Institutes & Labs
• Offices & Programs

This is a site-wide search. if you already know what you're looking for, try visiting a section of the site first to see A-Z listings.

Results for " "

Section Menu

Introduction.

Non-human animals are used in medical and other scientific research at academic institutions, hospitals, and in industries such pharmaceuticals and cosmetics. Scientific research on animals helps develop antibiotics and other medications, as well as immunizations and surgical procedures.  Animals are used in the testing of consumer products such as perfumes and shampoos.  Animals are also used to educate students in biology, medicine, and related fields.  We will call all such efforts “animal research.” 

Rats and mice are the main animals used, but also used are birds, reptiles, amphibians, fish, and other mammals.  In the course of animal research many animals suffer discomfort, fear, and pain, and some animals die.  Of course, many animals in the wild suffer and die also, hence the famous expression:

“nature red in tooth and claw.”

Animal research is morally controversial.  Many scientists just assume that it is morally permissible, but animal rights advocates claim that it is not.

Arguments For Animal Research

Humans use animals for their purposes and do so for the most part without thinking the practice needs moral justification.  People have used and continue to use animals for transportation, farming, recreation, companionship, sport, and food.

Likewise the use of animals in research has occurred largely without researchers thinking they needed to morally justify this practice.  But if a justification is thought to be needed, the main one given by supporters is that such research brings great benefit to humans, enough benefit to outweigh any possible animal suffering or sacrifice involved.

Furthermore, those who support animal research usually hold that most scientific results obtained through animal research are not available in any other way or that the use of animals in research is more effective than other possible methods that might be used to obtain this scientific knowledge.

Here is a sketch of some important claims assumed or given in support of animal research:

• It is morally permissible for humans to use animals, that is, to raise them and keep them for our purposes, to do things with them and to them, and to make things out of them.  For example, we may eat them, use them for clothing, use them for farm work, put them in service as guard animals and guide animals, use them as pets, do research on them, etc.
• Animals have no right to life, no right to live their own lives, and no right not to be used for human purposes.
• Any suffering endured by animals in research contexts is justified by the benefits to humans from such research.
• Computer modeling and other study methods not involving animals would not be able to fully replace the use of animals in research because we would not gain as much knowledge by these other techniques.

In recent years there has been some discussion among ethicists about animal rights and how we should treat animals, and as a result we can add a few modifications or qualifications that those who support animal research usually now will concede:

• Animals may have no right to life, but they deserve some sort of moral consideration that disallows some kinds of treatment of animals.  For example, it would be wrong to torture animals for fun.  If possible, they should be treated humanely and not made to suffer unnecessarily.
• Controls should be in place to protect research animals from unnecessary harm (pain and suffering).

This modern qualified version of support for animal research grants animals some sort of moral consideration or moral status; some animal research advocates may go so far as to allow that animals have some limited moral rights.  Most people grant that it would be wrong to make or allow an animal to suffer or torture an animal just to provide us with amusement or entertainment.  This could be stated in terms of human moral obligations – we have a moral obligation not to torture animals – or in terms of animal rights – animals have the right not to be tortured.  Also, there have been concerns during the last few decades that animals in zoos should be provided with better, more realistic habitats so that they have more of a life.  None of this is taken to preclude scientific research, though it might complicate it, but it is now commonly recognized that steps should be taken by researchers, sometimes at significant cost to the research project, to treat research animals humanely and limit any suffering.

An example of a defender of a more or less traditional view supporting animal research is Carl Cohen.  Cohen thinks that the tremendous benefit to humans from animal research outweighs any possible suffering on their part.  Efforts are and should be made to prevent mistreatment of research animals.  Cohen does not believe it makes sense to speak in terms of animals having moral rights, even limited rights not to be tortured, though Cohen would think it is wrong to torture animals.  Cohen’s view is that to have moral rights, a creature must have the capacity to have their own moral duties or engage in moral reflection or deliberation.  While humans can do this, non-human animals cannot.  Research animals therefore are not part of the moral community and can have no moral rights.

Animal Rights Advocacy

A position against traditional and more modern views supporting animal research is represented by diverse opponents we will group together as “animal rights advocates.”  Animal rights advocates often concede animal research has benefitted humans, though some advocates believe the benefit has been overblown and could have been provided in other ways.  But on their view no benefit from animal research could make such research morally permissible.

A number of distinct views are held by animal rights advocates:

• Animals are not on this earth to be used for human purposes.  They have their own lives.
• Animals have moral rights which are violated by using them for research or killing them for food or clothing.
• Animals used in research are often mistreated, despite the presence of controls meant to prevent this.
• Any human benefits through animal research are outweighed by the suffering of those animals.
• Benefits from animal research are greatly exaggerated: many research results are insignificant or useless (because animals are not like humans, results are often inconclusive) or could have been obtained in other ways.

Utilitarianism and Animals

Probably the most important theoretical perspectives from animal rights advocates come from Peter Singer and Tom Regan.

One tradition in ethics is that when faced with several alternative courses of action, one should choose the course of action that will result in the greatest good or happiness for the greatest number.  Versions of this tradition are called “utilitarianism.” 

One interpretation of utilitarianism interprets the “greatest number” to mean the greatest number of human beings.  A different view of “greatest number,” one represented by Singer, claims we should take into account not just human beings but any creature who can have conscious experience, feel happiness, and experience pain and suffering.  In judging the rightness or wrongness of a practice, everyone’s interests, happiness, pain, and suffering, including those of research animals, need to be taken into account. 

What of the claim that research benefits to humans outweigh any possible suffering of research animals?  According to Singer, the suffering of research animals is on par with that of humans, so for such research to be justified by future benefits, those future benefits would have to be able to justify it if the research were carried out on human infants.  Only if the pain, suffering, and other harm to human infant research subjects were considered justified by future benefits would it be justified to use animals instead of infants.  If one objects that human infants have greater potential than animals, and so should count for more or count in a more significant way, Singer suggests we consider whether we would do such research on brain-damaged infants who have no more intellectual potential than animals.

Singer and those who agree with him are not advocating we test new drugs on normal infants or brain-damaged infants instead of on non-human animals.  They merely want to make us see that we have no real grounds to consider only the interests of humans and treat animal interests, happiness, and suffering as if they don’t really matter.  Singer considers the view that human lives and interests are preferable to animal lives and interests to be a prejudice, a prejudice of “speciesism” that he considers analogous to racism.  Singer thinks we should consider speciesism wrong just as we consider racism wrong.

Singer at times speaks of animals as having rights.  His view that animals have interests and can experience happiness, pain, and suffering is consistent with them having moral rights, but note that, traditionally, utilitarians think of moral rights as akin to “useful fictions” rather than ultimate “metaphysical” possessions of conscious beings.

Regan’s Defense of Animal Rights

For Tom Regan, to say human beings have moral rights to life and liberty means others are not free to harm individuals or ordinarily interfere with their free choices.  Why do humans have moral rights to life and liberty?  Regan thinks it is because humans are subjects whose lives matter to them; a human being is (in his terms) a “subject-of-a-life.” 

But then, Regan notes, nonhuman animals are likewise subjects-of-a-life.  Nonhuman animals are aware of what happens to them and what happens to them matters to them.  Their lives can go “better or worse for them.”  They are subjects, not just objects, and one can say in the case of a nonhuman animal there is “somebody there.”   So, according to Regan, like humans, nonhuman animals have moral rights to life and liberty.

Regan holds that the use of animals in research violates their moral rights.  Subjecting an animal to suffering and death as part of scientific research violates the animal’s rights to life and to live that life in a way meaningful to the animal.  Their rights “trump” any purported justification of animal research as benefitting humans.

Regan is suspicious of the common claim that human benefits justify animal suffering anyway.  No one has ever worked out any kind of intelligible methodology that would enable one to compare benefits to one species with the harm to another species so as to show the former outweighed the latter.  The usual assumption seems to be that the suffering of an animal counts for less than the suffering of a human, but Regan questions this.

Issues in the Dispute

The controversy between the views supporting animal research and the view of animal rights advocates involves disputes about both factual (empirical) and moral issues.  Disputed factual issues include:

• whether scientific results obtained through animal research are significant
• whether the same or similar results could have been obtained through other means, and
• whether effective controls are in place to protect research animals from mistreatment.

Moral issues include:

• the moral status and moral rights, if any, possessed by nonhuman animals, and
• whether research animal suffering is justified in light of the benefits of such research to humans. 

This latter issue has empirical aspects too, because it involves answering factual questions of how much suffering occurs to research animals and how much humans really benefit from animal research.

A thorough discussion of all these issues is too much for this introduction, but the following comments on some of the issues may help you decide on your position on the morality of animal research. 

Factual issues :  It seems beyond argument that the use of animals in medical research has benefitted humans in many ways, for example in developing immunizations for measles and polio, in the development of antibiotics, and in the development of surgical techniques such as organ transplants and joint replacements.  Developed through animal research, vaccines for rabies and distemper have benefitted family pets as well.  It’s hard to imagine all this being done by computer modeling, and in fact much of this was done before computers were commonly available.  But it is worth considering whether, going forward, for some kinds of research more use of testing by means other than on animals might be just as effective.

In the context of research in the United States, controls are in place or being put into place to try to minimize animal suffering.  Whether or not these controls are fully effective and optimal is open to debate.  In this regard research seems to have come a long way from practices of decades ago, but we may need to police current policies better or put in place more stringent ones.

Moral issues :  The moral issue of whether human benefit justifies animal suffering and sacrifice itself has both moral and factual aspects:

• what constitutes human benefit (moral) and how to quantify that (factual)
• how to value the life of a research animal (moral)
• what constitutes animal suffering and sacrifice (moral) and how to quantify that (factual), and
• how to compare benefits and sacrifices across species (moral and factual). 

Regan is correct that the math of any “justification equation” is rarely even discussed, much less spelled out in any noncontroversial fashion.  In other words, there is no clear way to precisely quantify the suffering of research animals and compare this amount to a calculated quantity of human benefit to see if one outweighs the other.

In another respect, some people might seem confused about the issue of justification itself, sometimes assuming no justification is needed and yet at other times thinking animal research is justified by human benefit, as if justification were needed.

Obviously a key moral issue in the dispute is the precise moral status of nonhuman animals.  The moral status of something is whether the thing is a moral agent and/or a moral patient, whether it has moral rights, and if not whether it deserves some other sort of moral consideration.  For most people the sense of moral patiency possessed by such animals is very limited and gives them limited rights.  They may have the right not to be harmed for fun.  (But not everyone who believes this would be comfortable talking of such animals as possessing rights.  They might be more comfortable saying such animals deserve some moral consideration.)

Animal rights advocates of course would be comfortable with the view that animals are full-blown moral patients; Regan claims they have a right to life.  Animal right advocates just disagree here with Cohen that animals are not part of the moral community.  They are not moral agents, but they are moral patients.

Why do some things have a different moral status than do other things?  It might be that we implicitly base the moral status of something on some physical or metaphysical feature of that thing.  So for instance human beings are thought to have moral rights to life and liberty while trees do not because humans are conscious, rational, can express wishes and desires, have their lives matter to them, have an interest in their futures, etc. (physical features in the broad sense -  including mental), while the same cannot be said of trees.  Or human persons have immaterial souls (metaphysical features) while trees do not.  Or animals are considered to be subjects (a metaphysical category), just as humans are.

Regan thinks the moral status of a thing depends on it being the subject of a life, having a future that matters to it.  Regan’s type of view tends to see things as black or white.  If it is the subject of a life, it has the moral right to life, otherwise not.

To be consistent we should grant the same moral status to creatures that are relevantly similar physically or metaphysically, depending on what it is we think that grounds moral status.  Aliens from another planet who acted like human beings in certain essential ways might be given a similar moral status, though they were not human.  However, one could argue that moral status comes in degrees and is not absolute in the way Regan thinks.

Another consideration is whether the moral status of a being could be overridden by other factors.  So, for example, one might claim that nonhuman animals deserve a certain kind of moral treatment but in the case of crucially important research trying to save human lives that status can be overridden.

Carl Cohen and Tom Regan,  The Animal Rights Debate Peter Singer,  Animal Liberation Tom Regan,  Empty Cages

More Centers, Institutes and Labs

• Baker Research Lab
• Becevic Telehealth Lab
• Biomedical Informatics
• Cardiac Cell Physiology Lab
• Center for Education and Development
• Center for Health Ethics
• Center for Health Policy
• Center for Medical Epidemiology and Population Health (CMEPH)
• Center for Patient-Centered Outcomes Research
• Center for Precision Medicine
• Child Health Research Institute
• Christopher S. Bond Life Sciences Center
• Cognition, Aging, Sleep, and Health Lab (CASH)
• Cognitive Neuroscience Laboratory
• Cosmopolitan International Diabetes Center
• Craniofacial Research Center
• Dalton Cardiovascular Research Center
• Electron Microscopy Core Facility
• Ellis Fischel Cancer Center
• Fay Research Lab
• Functional Assessment Screening Team
• Health Informatics in Diabetes Research (HIDR) Core
• Health Intervention and Treatment Research Lab
• Immunity & Autoimmunity Research Lab
• International Institute of Nano and Molecular Medicine
• Lei Research Lab
• Microcirculation Laboratory
• Missouri Health Information Technology Assistance Center
• Missouri Orthopaedic Bioskills Laboratory
• Mizzou OneHealth Biorepository
• Mizzou Sleep Research Lab
• MU Center for Translational Neuroscience
• MU Student Health Center
• MU Surgical Center for Outcomes Research and Effectiveness (MUSCORE)
• Narrative Medicine and Health Innovation Lab
• Pulmonary Imaging Research Lab
• Rural Health Research Center
• Shelden Clinical Simulation Center
• Subramanian Research Lab
• Thompson Center for Autism and Neurodevelopment
• Thompson Laboratory for Regenerative Orthopaedics

Happenings at MU School of Medicine

Stories that inspire.

University of Missouri Researchers Pursuing Groundbreaking Living Knee Joint Replacement

Ellis Relishes Role as Physician and Educator at Springfield Clinical Campus

Leary honored with 2023-24 Shared Governance Award

Rural Scholarships Announced for 2023-24 Academic Year

See All News

Columbia, MO 65212 Contact

Emergency Information

Sign up for our monthly newsletter

Copyright © 2023 — Curators of the University of Missouri . All rights reserved. DMCA and other copyright information . Equal Opportunity/Access/Affirmative Action/Pro Disabled & Veteran Employer . For website issues, contact MU Health Care Communications . Contact the MU School of Medicine .

We won’t always have to use animals for medical research. Here’s what we can do instead

Associate Director, CSIRO Futures, CSIRO

Strategy Manager, CSIRO Futures, CSIRO

Disclosure statement

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

CSIRO provides funding as a founding partner of The Conversation AU.

View all partners

Animals have been used for medical research for thousands of years, dating back to ancient Greece where the first dissections were performed.

These days, one of the main uses of animals is to ensure the safety of medical products before they’re trialled in humans.

But in addition to the important ethical reasons for minimising animal use, the reality is sometimes animals just aren’t that good at predicting human responses. No animal model, for example, has captured all the human characteristics of complex illnesses like Alzheimer’s disease or chronic inflammatory demyelinating polyneuropathy (a neuromuscular disease). This makes is hard to develop effective treatments and cures.

Thankfully, researchers are making progress in developing a collection of alternative approaches, called “non-animal models”. A new report from our team at CSIRO Futures examines the potential of non-animal models and the actions Australia will need to take to pursue their use.

Read more: Can we ethically justify harming animals for research?

What are non-animal models?

Non-animal models are an alternative set of models that use human cells, tissues and data.

These have the potential to better mimic human responses. In doing so, this can more accurately predict if a medical product is likely to fail, allowing reinvestment in products that are more likely to succeed.

Computer simulations or “in silico models” are one example. These can be used across the medical product development process to complement – and in time potentially replace – other model types. They can be used in drug studies to model a drug’s behaviour within the body, from cellular interactions to processes that involve multiple organs.

Complex three-dimensional biological models are also maturing quickly. Examples include:

organoids – organ “buds” that can be propagated from stem cells or taken from biopsies

organs-on-chips – cells cultured in a miniature engineered chip. These attempt to replicate the physical environment of human organs.

What can we use non-animal models for?

In theory, we can use non-animal models for everything we use animal models for – and more.

Simple non-animal models (human cells cultured over a flat surface) are already used to help identify drug targets due to their ability to test a large number of compounds and experimental conditions.

In the future, non-animal models will reduce – and eventually replace – animal use across a range of applications:

• screening potential drugs to see how well they work
• toxicology (safety) testing
• helping to screen, select and stratify shortlisted participants for clinical trials. This might include an assessment of their unique response to a potential drug.
• using patient cells to identify the treatment most likely to help that individual.

Outside of medical products designed for humans, non-animal models can also support innovation in veterinary and agricultural medicines, cosmetic testing and eco-toxicology.

An export opportunity for Australia

Non-animal models present an economic opportunity for Australia, where the models, their components, and surrounding services could be exported to the world.

Our novel economic analysis sized the potential Australian market for two non-animal models: organoids and organs-on-chips. Other models were unable to be sized due to a lack of global market data.

We estimate the Australian organoid market could be worth A$1.3 billion annually by 2040 and create 4,200 new jobs.

The organs-on-chips market could be worth A$300 million annually by 2040 and create 1,000 new jobs. This estimate is lower as this technology is currently less advanced but holds the potential to grow significantly beyond 2040.

Read more: Mechanical forces in a beating heart affect its cells' DNA, with implications for development and disease

Several Australian entities are already contributing to these opportunities. The Murdoch Children’s Research Institute, for example, provides stem cell and modelling expertise as part of reNEW , a €300 million international collaboration.

Another example is from Schott Minifab , an international biotech and medical device company with Australian roots, which has successfully established scaled production of non-animal model components in Australia for domestic and export markets.

Making it a reality

Non-animal models have already begun to complement and replace animal use in some areas, such as identifying drug targets.

However, accelerating their development and adoption across a wider range of applications will require further technical advances to lower cost and validate their performance as superior models.

Australia has several research strengths in this field but we need a concentrated effort to help our research make it through to real world impact.

Our report makes ten recommendations for supporting Australia’s pursuit of these opportunities. Critical activities over the next five years include:

• coordinating local capabilities
• investing in upgraded infrastructure
• creating and collating data that compares animal and non-animal model performance.

Governments, industry and research must collaborate to deliver against these actions. Success will only come from collective efforts.

Read more: Is it time for Australia to be more open about research involving animals?

• Medical research
• Drug development
• Research ethics
• Animal testing

Senior Enrolment Advisor

Associate Professor, Occupational Therapy

GRAINS RESEARCH AND DEVELOPMENT CORPORATION CHAIRPERSON

Faculty of Law - Academic Appointment Opportunities

Audience Development Coordinator (fixed-term maternity cover)

16 Integral Pros and Cons of Animal Experimentation

Over 25 million animals are used for experimentation in the U.S. every year. Monkeys, rabbits, cats, ferrets, pigs, sheep and chimpanzees are just some of the animals used for biomedical experiments, science education, and product and cosmetics testing. Some animals, however, are more preferred by laboratories. In fact, over 90% of test subjects are mice, birds and rats.

Many proponents of animal experimentation claim that the process is for a good cause. Better to use animals than humans for testing, right? After all, they are below humans in the natural chain of things. But, as English philosopher and social reformer Jeremy Bentham puts it, it is not a question of whether they can talk or reason, but whether or not they suffer. Considering that animals cry and show discomfort, it is safe to conclude that they feel something.

Unfortunately, vivisection, or the practice of animal experimentation, is perfectly acceptable and legal. It is the worst form of animal abuse that is institutionalized and sanctioned by our society. Despite the fact that the conditions of animals in labs are monotonous, stressful, and very unnatural for them, invasive experimentation persists, and even when the endpoint is death. Whether animal experimentation is good or bad really depends on who you are asking. But, if it is condone by society, then there must be some advantages to it, even if the benefits are at the expense of animal lives.

List of Pros of Animal Experimentation

1. Contributes to many cures and treatments that save many human lives The majority of the medical breakthroughs that have happened in the last 100 years were direct results from animal research and experimentation, according to the California Biomedical Research Association. Insulin, for example, was discovered through an experiment where dogs have their pancreases removed. The Anderson Cancer Center animal research also associated the vaccine for Hepatitis B with experimentation on chimpanzees. Without these experimentations, thousands, if not millions, of diabetic patients and those with hepatitis B would have been killed every year. The same facility also said that the chimps serve as humanity’s only hope for finding a Hepatitis C vaccine.

2. Provides adequate living, whole body system test subject No other living thing in this planet has the closest anatomical structure as humans than animals. A human body is extremely complex that cell cultures in a petri dish cannot provide sufficient test results or proof that a cure or product is effective. Testing a drug for side effects, for example, requires a circulatory system that will carry the drug to different organs. Studying interrelated processes is also best done in subjects with endocrine system, immune system, and central nervous system, something humans and animals have. What about the use of computer models? They would require accurate information that is gathered from animal research.

3. Humans and animals are almost identical in many ways The DNA of chimpanzees are 99% similar with humans, while the genetics of mice are 98% similar. Humans and animals are also biologically similar, having the same set of organs, bloodstream and central nervous system, which is why they are affected with the same diseases and health conditions. Given these circumstances, animals used in experimentation do serve as appropriate research subjects.

4. Provides an ethical alternative for testing Most people would say that it is unethical to use humans for invasive experimental procedures, especially when it can result in death. The lives of human volunteers must not be endangered when testing medicines for side effects or potential toxicity. Ethical consideration must also be made when genetic manipulation would be involved. Human trials must be preceded by animal testing, as stated by the World Medical Association Declaration of Helsinki. But, if animals could talk, they would probably demand the same ethical considerations.

5. Offer benefits to animals themselves Animal experimentation is not only beneficial to humans but animals as well. If the vaccines were not tested on them, a lot of them could have died from rabies, infectious hepatitis virus, anthrax, feline leukemia, and canine parvovirus. Remedies for hip dysplasia and glaucoma were also discovered through animal testing. But the real highlight is that vivisection helped kept endangered species, such as the California condor, the tamarins of Brazil, and the black-footed ferret, from becoming extinct. This is why animal testing is endorsed by the American Veterinary Medical Association.

6. Allow researchers to study a test subject for a whole life span Humans can live up to 80 years or more, which means some scientists would be dead before others results will be gathered. Laboratory mice, on the other hand, only live for 2 to 3 years, giving researchers an opportunity to study effects of genetic manipulation or treatments over an entire lifetime. In some cases, they can continue to study across several generations. This is why mice and rats have been used for long-term cancer research.

7. Animals are protected from abuse and mistreatment Contrary to what most opponents believe, animal research is highly regulated, with laws enacted to protect animals. Since 1966, the federal Animal Welfare Act have been regulating animal experimentation.

• Research animals must be provided with shelter that follows minimum housing standards, such as the right-sized enclosure, recommended temperature, access to clean food and water, etc.
• Veterinarians must regularly inspect the animals and their living conditions
• Each research facility must set up an Institutional Animal Care and Use Committee (IACUC) that will approve all proposals to use animals for experimentation.
• The IACUC will be responsible for enforcing humane treatment of animals.
• Research facilities funded by the US Public Health Service (PHS) must comply with the policies on Human Care and Use of Laboratory Animals imposed by PHS.

8. Fewer animals are used in research than as food for humans Compared to the amount of chicken, cattle, sheep and pigs that humans eat, relatively few of them are used in experimentation. With consideration to the medical progress and advancement such tests provided, it is a small price to pay. To illustrate, for every chicken used in research, an equivalent of 340 are used as food.

List of Cons of Animal Experimentation

1. Cruel and inhumane treatment Protocols in animal testing are often painful to the test subjects. They are forced fed, deprived of food and water, restrained physically for prolonged periods, inflicted with burns, wounds and pain to test for healing process effects and remedies, and even killed through neck-breaking or asphyxiation. This is according to the Humane Society International. When testing to evaluate irritation caused by cosmetics, for example, a rabbit’s eyes will be held open by clips so it cannot blink away the products being evaluated. The clips usually stay on for days, and to ensure the rabbits stay in place, they are incapacitated. Some experimentation also involves using lethal doses of certain chemicals to determine how much can kill animals.

2. Animals make poor test subjects This statement is a direct contradiction from what proponents believe about how closely related animals and humans are anatomically and biologically, because of the many metabolic, cellular, and anatomical differences between the two species. Using rats for toxicity, for example, must not be accepted as reliable since humans are nowhere close to being 70-kilogram rats, according to Thomas Hartung, professor of evidence-based toxicology at Johns Hopkins University. This is further supported by the 2013 study in the Archives of Toxicology that states that the lack of direct comparison of human data versus that of a mouse makes the usefulness of research data dubious.

3. Success in animal experimentation does not equate to human safety When the sleeping pill thalidomide was tested on pregnant rats, mice, cats and guinea pigs, there were no incidence of birth defects, except when administered at extremely high doses. However, when it was used by pregnant women, it resulted in severe deformities affecting 10,000 babies.

• The arthritis drug Vioxx, which turned out great on animals was really bad news on humans because it caused more than 20,000 heart attacks and sudden cardiac deaths.
• A majority of the drugs that passed animal tests, 94% to be exact, failed in human clinical trials.
• 100 of the drugs designed to treat stroke worked on animals, but completely failed in humans
• Over 85 vaccines for HIV worked well in primates, but failed in humans

4. Can lead to misleading research Some medicines and products that are harmful to animals are actually valuable to humans. Aspirin, for example, was almost shelved because it proved dangerous for animals. Imagine what would have happened if aspirin was completely taken off the pharmaceutical list? There would have been no way to lower the risk of organ transplant being rejected.

5. Most animals used in testing and research are not protected by the Animal Welfare Act (AWA) As of 2010, only over 1 million animals are covered by the AWA, leaving around 25 million more unprotected from mistreatment and abuse. These include birds, fish, mice and rats. And because vivisections within laboratory walls are regulated by the committee that the facility itself selected, animal subjects are even more at risk of being treated like prisoners in a hospital for their entire existence. One very good example of a clear violation of AWA was discovered in a federally funded facility in Louisiana, New Iberia Research Center (NIRC). The animals were so stressed out psychologically that they resorted to self-mutilation. The rest of the 337 violations that NIRC committed were caught on a video footage, showing the heartbreaking conditions of the animals. But this facility is just one of the many that violates AWA.

6. There are less expensive alternatives to animal experimentation Despite what proponents insist, cell cultures in a petri dish, or in vitro (in glass) testing, are not exactly useless or insufficient. They can even produce results that are more relevant than animal experimentation. The same thing is true when using artificial human skin as a test subject, instead of animal skin. Virtual reconstructions of human molecular structures done through computer models also have the capacity to predict toxicity levels of substances, so no need to poison animals to collect data and draw conclusions. And, when testing for adverse reactions, administering small doses on humans, also known as microdosing, also offers an alternative. Combined with blood analysis, results will be produced.

But what is really important is that these alternatives are less expensive than animal experimentations. In glass testing, for example, only costs $11,000, which is less than $21,000 than an “unscheduled DNA synthesis”. A phototoxicity test that doesn’t use rats only cost $1,300, which is almost $10,000 less than its animal-based equivalent. These only shows that animal tests are wasting plenty of government dollars allocated for research.

7. Plenty of animal lives are wasted Considering all the tests that failed, not to mention other non-experimental factors that affect animals, there is a significant number of animal lives wasted for nothing. They suffer or get killed during the experiment, and suffer the same fate after the experiment. But what is really inhumane and unethical are the poor research procedures used by some facilities. Serious flaws were discovered in plenty of studies in the UK and the U.S. that use rodents, according to a peer-reviewed study conducted in 2009. Selection bias was a major problem, but even with randomization and blinding technique used, proper selection of animals still failed. There is also a lack of hypothesis or objective related to the study.

8. Medical breakthroughs need not involve animals Is animal experimentation really that necessary in discovering treatments and cures? Opponents argue that there is really no evidence of its vital role in major medical advances. If funds and resources are focused on animal-free alternatives, more humane, ethical and inexpensive solutions. One such alternative that should be given full support is the microfluidic chip, also known as organs on a chip. This involves the use of chips to achieve certain functions of a human body, such as mix, pump and sort. The chips are lined with human cells so they work similar to human organs. With this alternative, researchers can no longer use the excuse that they need a living, whole-body system to run experiments.

• Skip to primary navigation
• Skip to main content
• Skip to primary sidebar
• Skip to footer

Opinion Front

Weighing the Pros and Cons of Using Animals in Research

Debates have roared in the medical fraternity related to animal research since ages. Have we achieved milestones in curing diseases by testing and killing meek animals? Are such medical breakthroughs worth their lives? If animals can't speak, does it mean that we can use them as we wish, just because we're powerful? This article throws light on these various issues.

Debates have roared in the medical fraternity related to animal research since ages. Have we achieved milestones in curing diseases by testing and killing meek animals? Are such medical breakthroughs worth their lives? If animals can’t speak, does it mean that we can use them as we wish, just because we’re powerful? This article throws light on these various issues.

Vivisection is a social evil because if it advances human knowledge, it does so at the cost of human character. ~ George Bernard Shaw

When I look into the eyes of an animal, I don’t see an animal. I see another living being. I see another soul like me. I see a friend ~ Unknown

Of late, the debate on animal research has been a highly sensitive topic in the media. While animal testing by scientists has been fraught with controversy, it’s still a fact that animals are captured for experiments. This often rages heated debates between animal lovers and those who support such experiments. Discover both sides of the coin in this write up.

The Pros and Cons

Rats share certain similarities with the human biology. Their hard luck, it seems. This has made them one of the most used animals in experiments and laboratory testing. Consequently, numerous tests on animals have led to path breaking discoveries in medical science. On the contrary, animal research ethics and the integrity and morality of such tests have been questioned by environmentalists.

Pros PETA (People for the Ethical Treatment of Animals) supporters will stand in unison against the support of animal testing. However, when we view various animal testing pros, we realize that there are several positive aspects to it as well.

• Various dangerous diseases like herpes simplex, hepatitis B, polio, rabies, malaria, and mumps have been treated owing to medications developed from tests on animals.
• Results through medical research on animals have led to improvement in medical procedures like blood measurement, lung disease diagnosis, heart disease diagnosis, and various pacemaker technologies.
• One of the most important techniques in medical surgery, anesthesia, has been developed after it has been tested on animals.
• Animal research has also been able to benefit cats and dogs in certain ailments. Moreover, the nutrition of cats and dogs has been improved after repeated animal tests.

Cons Animal testing statistics are alarming. To discover new medicines and vaccinations, millions of animals are killed every year all across the globe. Animal rights are lost in oblivion when it comes to animal testing ethics. In this part, we focus on the demerits.

• Animals go through severe pain during the tests. Most testers claim they use anesthesia to conduct the tests. However, can pricking needles and using chemicals on animals be painless? Who knows if they use anesthesia safely. Just because animals can’t speak, it is not morally correct to subject them to such treatments.
• Months of torture leads to loss of eyesight, organ failure, and many more dangerous consequences on the animals’ health. Just to see the effects of chemicals, animals are imprisoned and observed over a certain period of time. Meanwhile, they go through hell and eventually die. A majority of animals are killed in the process.
• Animal testing in the cosmetic industry is another issue that has raised serious concerns over animal safety. Why there is a need to kill animals for enhancing beauty that is often harmful for skin is still not known. It is always better to adopt natural means for beauty.
• Animals have been forced to mutate and produce cross springs. Embryos of different animals are injected into a different animal’s body.
• Animal cloning is another phenomena that has been tried several times. Why reduce the dignity of animal lives? Mostly, hybrid animals and cloned ones are either diseased, malformed, or even dead.
• Animal cruelty has risen to peaks after stem cell and tissue culture has become popular. Scientists are suggesting to find a cure for cancer by trying all experiments on animals. How ethical is it?
• A study suggests that less than 2% of illnesses that affect humans are ever found in animals. Even rodents (rats), that are mostly used in cancer research, rarely have human form of cancer (lung cancer etc). Why are they still used in such researches?

This topic will always be debated among scholars, animal lovers, and scientists. Humanity has always been caught in dualities. While there is a positive side to one aspect, the negative side also exists. Animal research through animal experimentation has been an integral part of medical research. Yes, this system is inhuman, unethical, and simply morally wrong, but always remember, we all agree to disagree.

Like it? Share it!

Get Updates Right to Your Inbox

Further insights.

Privacy Overview

• South Korea
• Other Countries
• Interesting Facts About

6 Pros and Cons of Animal Testing for Medical Research

Researchers, doctors, scientists, and pharmacists are all working around the clock to come up with vaccines, medications, and cures for the diseases and illnesses present in our world today. But because a lot of these solutions need testing and experimentation before they’re formulated just right, they need to go through preliminary uses. Oftentimes, testing is performed on animals which is frowned upon by many organizations and individuals.

List of Pros of Animal Testing for Medical Reasons

1. No Need to Test on Humans For a medication to be proven effective, it needs to show real results when used for the conditions it’s intended for. But because testing a experimental treatment on humans could prove fatal or dangerous to the health, using animals first to find out how it will react with living creatures will help scientists better adapt their formula for effectiveness.

2. Accurate Results Although there are alternate methods of testing medications and cures, the results they render might not be relevant to humans. Because some animals can be used as better representation of humans, the test results gathered from animal testing can be assumed the same for humans.

3. Faster Development Unlike other methods of medication testing, animal testing is a much faster route because developers can easily see what or why things happen, as opposed to depending on observing reactions at a molecular level.

List of Cons of Animal Testing for Medical Reasons

1. Animal Cruelty Many of the animals that are used in labs for medical research are left traumatized, permanently disabled, or even dead. This raises very serious red flags for lots of animal rights groups and activists who believe animals should be given the same compassion as humans.

2. No Guarantee The fact is, even if animal testing can eliminate some dangers of using new meds on humans, a medication needs to be tested on humans prior to release. This means some of the perils of using a certain formulation could only become apparent once it’s used on a living person, which means even with animal testing, there’s no guarantee that it will be a hundred percent safe.

3. Costly Animals used for testing need to be sourced from legitimate breeders and suppliers that could bump up their prices to make bigger profits off of their creatures. This could spell massive expenses for researchers, as opposed to simply looking for willing volunteers who want to become part of the experimentation.

RELATED ARTICLES MORE FROM AUTHOR

6 Pros and Cons of Foreign Aid

6 Pros and Cons of Flu Shot

6 Pros and Cons of Flat Tax

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• Explore content
• About the journal
• Publish with us
• Sign up for alerts
• Book Review
• Published: 01 November 2001

Why Animal Experimentation Matters: The Use of Animals in Medical Research

• Judith K Blackshaw 1  

Heredity volume  87 ,  page 609 ( 2001 ) Cite this article

2099 Accesses

Metrics details

Why Animal Experimentation Matters: The Use of Animals in Medical Research.

E. F. Paul and J. Paul. Transaction Publishers, New Brunswick, USA. 2001. Pp. 224. Price $49.95, hardback. ISBN 0-7658-0025-X

This thought-provoking book comes out of the Social Philosophy and Policy Foundation, an independent corporation established to promote advanced research in political philosophy and in philosophical analysis of public policy questions. The use of animals for medical research is being threatened by animal rights activists who propose severe restrictions or abolition of experimental work.

In their essays, the eleven American authors challenge many flawed perceptions promoted by animal rights groups. These include misrepresentation of historical facts, and the contributions to human and animal health, by the use of experimental animals. Fortunately, activists efforts so far have not slowed down progress of biomedical and pharmacological research. In much of the world with epidemiological and nutritional challenges any animal activist agenda to shut down or hinder animal research is, as one author comments “fanatical, even suicidal”. Several authors go further and argue that to deny much of the world's population hope for vaccines and other medical cures is inhumanity towards humans.

Some animal rights groups concede that applied research is justifiable but that basic research should be prohibited. As the author of one essay points out, this view jeopardises both the advancement of knowledge and the remediation of human disease.

The question is raised of how human and animal interests can be balanced. The European view gives greater significance to animal interests than the American approach. However, both are closer to the human-priority view than either the UK or German statutes, which are more towards equality in human and animal interests.

Several authors argue from the evolutionary perspective in defending animal experimentation. They suggest that to disallow the acquisition of medical and agricultural knowledge would be a maladaptive strategy, that may endanger human survival. The philosophical bases of the animal rights groups are discussed and the reader is required to carefully follow often unfamiliar arguments. However the end result is well worthwhile.

At the end of the book's introduction the hope is expressed that, ‘these essays will advance public debate on this vital issue.’ It is hard to imagine that the general public will read such a book, but hopefully the scientists and students who carry out animal based research will use the arguments when explaining and justifying their research.

There is a useful index and I found the endnotes for each chapter interesting. I would have liked an alphabetical list of literature references at the end of the book.

It becomes evident after reading this book that animal rights movements are only sustainable in affluent societies. It is the responsibility of these societies to work towards the alleviation of diseases, which much of the world suffers. This book should be welcomed by the research communities in all countries where animal based research is conducted.

Author information

Authors and affiliations.

School of Veterinary Science The University of Queensland, St Lucia, 4072, Australia

Judith K Blackshaw

You can also search for this author in PubMed   Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article.

Blackshaw, J. Why Animal Experimentation Matters: The Use of Animals in Medical Research. Heredity 87 , 609 (2001). https://doi.org/10.1046/j.1365-2540.2001.0809a.x

Download citation

Published : 01 November 2001

Issue Date : 01 November 2001

DOI : https://doi.org/10.1046/j.1365-2540.2001.0809a.x

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

Quick links

• Explore articles by subject
• Guide to authors
• Editorial policies

Animal Behavior

On using animals in medical research, musings on a neal miller quote.

Posted September 3, 2016

The American Psychological Association ranked Neal Miller the 8th most influential psychologist of the 20th century.

I had the privilege of being Neal Miller's research assistant at the Rockefeller University on the first research that proved that biofeedback works.

In that research, we used a number of research rats, and animal rights activists attacked Miller for that. Here was his response:

There is sacredness of all life. But where do we draw the line? That's the problem. Cats kill birds and mice. Dogs exploit other animals by killing and eating them. Humans have to draw the line somewhere in animal rights, or we're dead.

I'm not sure that would convince vegans but perhaps this expansion of his argument will:

Research animals would never come into existence if not for their need in research. And research animals' lives are superior to that of wild ones. For example, wild rats and mice constantly must escape predators and rat/mouse traps, endlessly search for literal crumbs and water, and live in sewers, walls, basements and outdoors with temperatures ranging from frigid to sweltering. In contrast, a research animal, from birth, lives in a home that's warm, safe, and without predator. They get a ready diet of perfect food and water, and sleep on soft bedding. In adulthood, they die in the service of improving humankind.

Let's even assume that some of the animals experience pain before dying, as alas many people do. Let's weigh that against the fact that without research animals, medical research would have to be done using computer simulations or conducted earlier on humans, which would entail greater risk to people.

Computer simulations usually are inferior to animal-based research because no matter how many human characteristics are simulated--at great cost and time--the computer modeling can't as accurately represent how a treatment would work in humans.

Particular emphasis must be placed on the time element. Research animals are available immediately. In contrast, developing even that inferior computer model takes months or even years. As any patient with a serious, let alone life-threatening disease knows. every day without a better treatment, can well be a day of pain, fear , and perhaps avoidable death.

When the animal rights activists--many of whom eat animals!-- stop medical research and the computer modeling simply is inadequate, the researchers are forced into one of two choices, both inferior to animal-based research: In cases in which post-mortem analysis is required to see a treatment's benefits and side effects, of course, the research must be stopped thereby eliminating all chance of helping people with their disease. In other cases, the researchers must prematurely conduct the research on human beings, making people rather than the animals the first-line guinea pigs, at significant risk. Is that ethical?

Of course, most treatments tested on animals never come to market let alone dramatically improve human life. But a small percentage do. Treatments from blood transfusions to MRI diagnosis to deep brain stimulation for Parkinson's, and yes biofeedback, were made possible only because of animal research.

For animal rights activists to oppose using research animals is to argue for those animals never living to enjoy a well-above-average childhood and adolescence while delaying or prohibiting humans from getting potentially life-saving treatment. Such treatments not only improves their lives but that of their families.

In addition, those research discoveries relieve our already overtaxed medical system of unnecessarily long treatment.

Medical research even helps pets. When sick pet owners are helped, they're better able to care for their pets.

I love animals. I really do. My doggie Einstein truly is a member of our family and we treat him as such, even going to the butcher to get splinter-free bones cut into Einstein-friendly pieces.

But like Neal Miller, I cannot accept the arguments of extremist animal activist groups. How about you?

Marty Nemko's bio is in Wikipedia. His newest book, his 8th, is The Best of Marty Nemko.

Marty Nemko, Ph.D ., is a career and personal coach based in Oakland, California, and the author of 10 books.

• Find a Therapist
• Find a Treatment Center
• Find a Psychiatrist
• Find a Support Group
• Find Teletherapy
• United States
• Brooklyn, NY
• Chicago, IL
• Houston, TX
• Los Angeles, CA
• New York, NY
• Portland, OR
• San Diego, CA
• San Francisco, CA
• Seattle, WA
• Washington, DC
• Asperger's
• Bipolar Disorder
• Chronic Pain
• Eating Disorders
• Passive Aggression
• Personality
• Goal Setting
• Positive Psychology
• Stopping Smoking
• Low Sexual Desire
• Relationships
• Child Development
• Therapy Center NEW
• Diagnosis Dictionary
• Types of Therapy

Understanding what emotional intelligence looks like and the steps needed to improve it could light a path to a more emotionally adept world.

• Coronavirus Disease 2019
• Affective Forecasting
• Neuroscience

More From Forbes

Dangers of humans taking animal drugs and vice versa.

• Share to Facebook
• Share to Twitter
• Share to Linkedin

A woman gives a tincture to a cat.

Prescription drugs indicated for use in veterinary medicine can be dangerous for humans. Conversely, medications approved for human use can pose a serious hazard for animals. And at the same time, some therapeutics can be prescribed to humans and animals and may work for both, so long as this is done with the appropriate dosage and formulation.

Ever wondered about the fact that your cat may be taking the same medication as you are? For example, cats can be administered transdermal doses of mirtazapine (brand name is Remeron or Mirataz) as an appetite stimulant. Mirtazapine is approved by the Food and Drug Administration for the treatment of depression in humans. Appetite stimulation and weight gain are common side effects, which is why it can be beneficial for patients who are experiencing weight loss and decreased appetite. Similar benefits may be achieved for animals, too.

Veterinarians can legally prescribe an approved human drug such as mirtazapine in animals under certain circumstances. This is called an extra-label use, as the American Veterinary Medical Association explains . It entails prescribing of an approved drug in a manner that deviates from the drug’s approved labeling, yet meets the conditions set forth by the Animal Medicinal Drug Use Clarification Act of 1994 and FDA regulations. Here, deviations from FDA-approved labeling include use in another species, for another indication, at a different dose or frequency or route of administration.

The FDA is the legal authority in the U.S. to approve and regulate drugs for both humans and animals. A drug intended for use in animals is called a new animal drug. The FDA has a division named the Center for Veterinary Medicine which approves and regulates new animal drugs. And because every animal species responds differently to pharmaceuticals due to differences in physiology and metabolism, the FDA determines if a drug is safe and effective for a specific use in a particular animal species.

According to the National Community Pharmacists Association, the following four drugs that were developed and approved for humans are commonly administered to certain animals under the extra-label rubric: Diphenhydramine to help treat allergies, allergic reactions and motion sickness; hydrocortisone for raw, itchy or irritated skin; famotidine as a stomach acid reducer; and dimenhydrinate for motion sickness, though a better choice might be an FDA-approved animal treatment such as Cerenia (maropitant citrate).

Best Short-Term Health Insurance Companies Of 2022

Best health insurance companies of 2022.

But you don’t want to ever play veterinarian with the human drugs in your medicine cabinet. Consult your vet before using any of the above drugs for your pets.

Nor should you ingest medications intended for animal use just because you may recognize a familiar active ingredient. In other words, people shouldn’t use products marketed for veterinary use that have not been evaluated by the FDA for human safety or that are otherwise not suitable for human consumption. Those products may have adverse effects, including serious illness and death, when taken by people. Either the veterinary drug itself poses a considerable risk to humans, or the dosage or formulation.

Take xylazine, for instance. It is a non-opioid veterinary tranquilizer which is approved for animal but not human usage. Not only is the animal sedative dangerous when taken on its own by humans, fentanyl mixed with xylazine is known on the street as “tranq” and is fueling an alarming rise in overdoses and deaths.

Another example is the dissociative, hypnotic drug ketamine, which can be prescribed to humans for certain mental disorders. But ketamine has also become an illicit street drug used illicitly for recreational purposes. There are veterinary and human formulations of ketamine. The veterinary formulations are ten times stronger, which makes it potentially deadly if ingested by humans.

The reverse applies, too, that is, when animals use products intended for human use only, they can experience adverse effects such as serious illness and death. Some drugs are highly toxic and potentially lethal for cats, for example, bismuth subsalicylate and acetaminophen. The FDA lists drugs that are prohibited from extra-label use in animals.

In other instances, a drug such as fluoxetine—the active ingredient in the commonly used antidepressant Prozac—may have approved on-label uses in both humans and animals. For “lonely dogs with separation anxiety,” Eli Lilly marketed Reconcile in 2007, which contains fluoxetine and is specifically formulated for animals. Dogs are often prescribed fluoxetine . This isn’t a new phenomenon. Fifteen years ago the New York Times published an article on the rise in the practice of prescribing medications designed for humans to animals.

And then there’s the special case of the broad spectrum antiparasitic ivermectin which has long had approved uses in humans and animals. However, animal ivermectin products are very different from those approved for humans. In veterinary medicine, it is indicated to prevent and treat heartworm and intestinal worms. You may have seen ads on television for Heartgard, which prevents heartworm disease in dogs, and treats and controls intestinal worms in animals. One of two active ingredients in Heartgard is ivermectin.

In humans, a topical ointment containing ivermectin can be prescribed to treat issues involving lice and rosacea, while a tablet is used for parasites, including intestinal strongyloidiasis and onchocerciasis ( river blindness ) and lymphatic filariasis .

During the Covid-19 pandemic a controversy erupted around the use of ivermectin in humans to treat or prevent Covid-19. The FDA in December 2021 warned Americans not to use ivermectin for this purpose. The FDA stated that there wasn’t evidence to support ivermectin’s use against Covid-19.

The agency went further by reminding us “never to use medications intended for animals on yourself or other people.” While the latter statement is apt, technically it doesn’t apply to ivermectin as the product isn’t only for animals. Moreover, the statutory authority of the FDA does not extend to the issuance of medical advice or recommending against off-label uses of medicines.

While the FDA does not approve of ivermectin as a treatment for Covid-19, doctors can still prescribe it if they insist, however ineffective it appears to be for patients, as has been chronicled repeatedly in separate peer-reviewed studies during the past several years.

The FDA threw down the gauntlet when it posted a tweet in 2021 opposing the use of ivermectin: “You are not a horse. You are not a cow. Seriously y’all. Stop it.” This drew the ire of some physicians who believed the FDA had overstepped its boundaries. In a lawsuit, the FDA has since agreed to delete and never republish the infamous tweet and other similar posts on social media, according to Newsweek .

Broadly, we can say that drugs that have approved uses in both humans and animals can be prescribed, so long as this is done with the appropriate dosage and formulation. Further, human medications can be used for pets and other animals in a limited number of instances—under the extra-label regulation—but only if recommended by your veterinarian and dosed and formulated appropriately. Finally, medicines intended for use in animals only shouldn’t be taken by humans.

• Editorial Standards
• Reprints & Permissions

An official website of the United States government

The .gov means it's official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings
• Browse Titles

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

National Research Council (US) and Institute of Medicine (US) Committee on the Use of Laboratory Animals in Biomedical and Behavioral Research. Use of Laboratory Animals in Biomedical and Behavioral Research. Washington (DC): National Academies Press (US); 1988.

Use of Laboratory Animals in Biomedical and Behavioral Research.

• Hardcopy Version at National Academies Press

3 Benefits Derived from the Use of Animals

Animal studies have been an essential component of every field of medical research and have been crucial for the acquisition of basic knowledge in biology. In this chapter a few of the contributions of such studies in biomedical and behavioral research will be chronicled. These descriptions should be viewed within the context of the vast improvements in human health and understanding that have occurred in the past 150 years. For example, since 1900 the average life expectancy in the United States has increased by 25 years (U.S. National Center for Health Statistics, 1988). This remarkable increase cannot be attributed solely to animal research, as much of it is the result of improved hygiene and nutrition, but animal research has clearly been an important contributor to improved human health.

Despite the many advances and the projected results that will come through the use of animals, some individuals question the value of using animal models to study human disease, contending that the knowledge thus gained is insufficiently applicable to humans. Although experiments performed on humans would provide the most relevant information (and are used in clinical research conducted on humans when appropriate), it is not possible by commonly accepted ethical and moral standards or by law to perform most experiments on humans initially. It is true that not every experiment using animals yields immediate and practical results, but the advances that will be described in this chapter provide evidence that this means of research has contributed enormously to the well-being of humankind.

As a result of the acquisition of information and the development of techniques achieved through the use of animals, poliomyelitis is no longer a major threat to health in the United States. The number of cases of paralytic polio in the United States has declined as a result of vaccinations from 58,000 in 1952 to only 4 in 1984 (Office of Technology Assessment, 1986). Unfortunately, polio is still a major threat to health where the vaccine is not used. Indeed, in a number of African, Asian, and South American countries, the incidence of the disease has been rising, despite the availability of the vaccine (Cockburn and Drozdov, 1970). An estimated 500,000 cases occur around the world each year (Salk, 1983).

The use of rhesus monkeys for the study of polio began when Landsteiner and Popper (1909) showed that injection of spinal cord material from patients dying of polio caused paralysis in the animals. Flexner and Lewis (1909) promptly confirmed this result. To learn how to immunize monkeys to protect them against infection, researchers first used live virus, then formalin-inactivated virus from infected brain suspensions, and eventually modified live virus. A major breakthrough occurred when Enders, Weller, and Robbins (1949) showed that the virus could be propagated in cultured cells of non-neural origin. That set the stage for mass production of viruses that could be made into formalin-inactivated Salk vaccine or the modified live-virus Sabin vaccine (Salk, 1983).

Although the use of monkeys in polio research has decreased considerably, they are still essential to the production of both live and killed polio vaccines, which are routinely produced in monkey kidney cell cultures. The live vaccine is tested for neurovirulence in monkeys, and the killed vaccine is routinely tested for safety in monkeys.

• Acquired Immune Deficiency Syndrome

The recent emergence of acquired immune deficiency syndrome (AIDS) as a major health threat exemplifies not only the unpredictability of research needs, but also the criticality of animals in research. The similarity of simian AIDS, identified in rhesus monkeys at two primate centers, to human AIDS has allowed the disease in monkeys to serve as a model for the human disease. In monkeys, the virus that causes the disease has been isolated, infectibility studies have been conducted, and some experiments have provided preliminary indications of the possibility of vaccine development. This animal model might prove useful for testing the efficacy and safety of vaccines and therapeutic agents developed to prevent or treat the human disease (Institute of Medicine, 1986).

Recently, a new virus called feline T-lymphotropic lentivirus has been discovered. It resembles morphologically the human immunodeficiency virus (HIV) that causes AIDS, although differing antigenically, and causes a disease naturally in cats similar to AIDS. Thus, infected cats might prove useful as animal models for the study of certain aspects of human AIDS (Pedersen et al., 1987).

• Transplantation

The transplantation of skin, corneas, and various internal organs could not have become a safe and standard procedure without the knowledge of the biology of transplantation immunology acquired through the use of experimental animals. Some 30,000 Americans now alive have transplanted kidneys, and others survive with transplanted hearts and livers or retain their sight because of corneal transplants.

The treatment of burn victims was of particular importance to the British during World War II, and British biologist P. B. Medawar (1944) undertook to find relief for them through the transplantation of skin. For one of his models, he used freemartin cattle. A freemartin is a sexually maldeveloped female calf that is born as a twin of a normal male calf; male hormones that reach it through placental vessels usually make it sterile (Lillie, 1917). Experimentation showed that skin and other tissues could be transplanted with good, lasting success between the male and freemartin twins at any stage in their lives (Anderson et al., 1961). They were "tolerant" of each other's tissues because of prenatal exposure to each other's tissue antigens. Medawar and his colleagues sought to induce such tolerance in newborn mice. When newborns received skin transplants or received bone marrow from unrelated animals, they became forever "tolerant" of the new tissue (Brent et al., 1976). That discovery signaled a new era in immunology, with wide ramifications for health and the treatment of disease not only in humans, but also in animals.

Through a systematic study of the surface immune markers of specially bred strains of mice, Snell and Benacerraf provided the basis for much of the understanding that has led to the success of organ transplantation (Benacerraf, 1981).

In the past, young women with chronic pyelonephritis, patients with genetic polycystic disease, and people suffering from the aftermath of streptococcal infections were all vulnerable to chronic renal failure and death. Those people benefited from the invention of "artificial kidneys," which periodically washed blood and removed poisonous substances from it. The recipients of the benefit, however, had to undergo frequent, laborious, and uncomfortable procedures and had to rely on hospitals and mechanical devices.

The first extensive work with renal transplantation was reported in 1955 (Hume et al., 1955). At first, transplanted kidneys were rejected unless they were exchanged between identical twins. However, studies in dogs showed that administration of the drug 6-mercaptopurine after transplantation would prolong the survival of a transplanted organ from an unrelated person. This use of immunosuppressants ushered in the modern era of transplantation (Starzl and Holmes, 1964). These compounds, having been studied first in animals and proved to be effective, are now used in human transplant recipients.

The study of tissue antigens proceeded at the same time as transplantation work, first in mice and then in humans. Inbred (isogeneic) strains of mice had been created by repeated brother-sister matings. Ultimately, these strains became genetically identical, and the exchange of tissues and organs became possible. In the study of minor genetic differences between such strains, it became clear that some genes specify the cell-surface structures responsible for tissue recognition and rejection. "Transplantation antigens" can now be identified by tissue typing, and the most appropriate donors can be chosen for transplantation in both humans and animals.

A second revolution in transplantation was ushered in by the development of cyclosporin. This immunosuppressive agent was first used successfully in humans in 1983, after five years of toxicity and efficacy testing in mice, rats, and other animals. Since it became available for heart transplantation, survival after transplantation has improved significantly (Kupiec-Weglinski et al., 1984). Further progress is now occurring with monoclonal antibodies that seem to immobilize the cell-surface markers responsible for recognition and rejection. The hope is that such monoclonal antibodies, which have been developed and maintained in animals, will make it unnecessary to resort to complete immunosuppression of a transplant recipient. This would reduce the occurrence of infection and increase the rates of survival of transplanted organs.

• Cardiovascular-Renal Systems

Dogs have traditionally been used in cardiovascular-renal studies because of their relatively large size, which facilitates experimental procedures. For example, an early model of hypertension was produced by partially occluding the renal artery in dogs. Studies of renal function that use clearance techniques in unanesthetized animals are most often done in dogs. In the last two decades, however, some mutant rats have proved exceedingly valuable as animal models of human disease. The Brattleboro rat is an excellent example. It has diabetes insipidus and must drink 70 percent of its body weight in water each day. It cannot produce vasopressin, a hormone that plays an essential role in the kidneys' ability to regulate water excretion and blood pressure. Research on the Brattleboro rat has greatly increased our understanding of vasopressin's role in kidney and cardiovascular function, and that understanding might lead to the development of better drugs (and drugs with fewer side effects) for the treatment of clinical disorders (Sokol and Valtin, 1982).

The development of open-heart surgery is but one of many examples of the value of using laboratory animals. Working with cats and dogs, Gibbon built the forerunner of the present-day heart-lung machine (Deaton, 1974), which makes open-heart surgery possible. His research in the early 1930s included clamping off more and more of an animal's vasculature and detouring its blood through the heart-lung machine. The machine was further improved by the incorporation of a roller pump developed by DeBakey (DeBakey and Henly, 1961), which allowed the entire circulation to be shunted through the machine, which added oxygen to the animal's blood. The pump was first used and perfected in the animal laboratory and is now a standard, essential component of the heart-lung machine. As a result of these developments, more than 80 percent of infants born with congenital cardiac abnormalities now can be treated surgically and can lead normal lives.

Replacement of heart valves and segments of large arteries in the treatment of valvular heart disease was made feasible by dog studies done in the late 1940s and early 1950s (Gay, 1984). Before diseased heart valves could be replaced in patients, scientists had to study their design and use in animals. As with so many other drugs and operations, physicians and surgeons would not consider applying them to patients until they had proved safe and effective in animals, nor would the public accept them until their safety was proved. Each decade since then has seen improvements in the design, installation, and performance of these valves and other prosthetic devices. Because the ideal valve has not yet been developed, research is still in progress in many laboratories to further improve its capacities.

• Nervous System

The human brain is a structure of extraordinary complexity. Each of its 200 billion neurons (nerve cells) makes a few thousand to several hundred thousand connections with other neurons, muscles, or glands. Neurons use large amounts of metabolic energy to carry out a host of functions: the generation and conduction of impulses; the synthesis, transport, secretion, and uptake of transmitters; and the modification of structure and synaptic efficacy in response to activity and environmental perturbations (Kandel and Schwartz, 1985).

Many basic aspects of neuronal development can be studied in cell and tissue cultures, in brain slices, and in simple invertebrate neuronal systems. Computer simulations and noninvasive human studies can also provide important data on fundamental mechanisms of learning and memory. Yet there is no adequate substitute for animal studies in attempts to understand the complex behavioral and cognitive functions of the brain in health and disease.

Movement and Function

Our understanding of the nervous system and approaches to rational therapy of its disorders could not have come about without animal studies initiated by the physiologist Charles Sherrington (Eccles and Gibson, 1979). His studies on reflex mechanisms of the spinal cord in cats were continued by Eccles (1957), who described how excitatory and inhibitory processes work in the central nervous system. Today, neurosurgeons can remove some brain tumors with minimal damage to the motor system in part because scientists such as Sherrington discovered that localized electrical stimulation of the exposed brain of the dog could elicit discrete movements of the limbs.

Neurologists and neurosurgeons now examine electrical signals from the brain to diagnose and treat epilepsy, study levels of consciousness, localize brain tumors, diagnose multiple sclerosis, and study learning disabilities in children. Moreover, the applications of such essential tools for diagnosis and therapy as computed axial tomographic (CAT) scans and magnetic resonance imaging (MRI) were developed with research animals (Kandel and Schwartz, 1985).

The study of the nervous system and behavior is one of the major frontiers of modern science. A good deal is known about the anatomy and physiology of the brain and nervous system, but much remains to be learned about it as an organized assemblage of neurons and about how it is affected by environmental stimulation. The following examples provide an idea of how animals are used in studies of such subjects.

Postnatal Development of the Visual Cortex and the Influence of Environment

Hubel and Wiesel shared the Nobel Prize in 1981 for their studies of vision in cats and monkeys, including the development of visual functions in young animals (Barlow, 1982). The visual cortex of monkeys is not fully developed at birth; nerve cells are still growing and making connections with other nerve cells. In this process, normal development depends on visual stimulation during a critical period in early postnatal life.

As in humans, each eye of a monkey sees a slightly different view of the same object; normal binocular vision gives the impression of depth. If early in postnatal life one eye is occluded, the nerve cells for that eye in the visual cortex do not develop normally. Most of the nerve cells become responsive only to the open eye, as shown in recordings from cells of the visual cortex of anesthetized animals. In normal development, the visual cortex consists of alternating bands of reactive neurons from the right and left eyes; but in a monkey with an occluded eye, the regular alternation is weakened, and most neurons react only to the normal eye. These anatomical and physiological changes are the basis of blindness in the occluded eye.

Children with congenital cataracts or clouding of the ocular media for other reasons demonstrate a similar dependence of human vision on visual stimulation. Testing after restoration of normal vision has shown that the acuity of the previously occluded eye is reduced; the earlier in life the eye was occluded, the greater the degree of deficit. Animal experiments have also shown that correction of strabismus (squint) by surgery should be performed early in, or certainly before the end of, the critical period of eye-brain development to ensure normal vision (Wiesel, 1982).

The close correlation between the effects of visual deprivation observed in animals and the effects observed in the clinic suggests that they are based on similar physiological mechanisms. This correlation has been helpful in developing appropriate measures of prevention and treatment of neural eye disorders.

Another subject of behavioral research is memory. An estimated 5 percent of people over the age of 65 have severe limitations or even failures of memory and cognition; another 10 percent of the people over 65 have mild to moderate cognitive problems (Coyle et al., 1985). Specific conditions, such as Korsakoff's syndrome and Alzheimer's disease, affect mental functions and can cause extreme memory loss. Research on animals is improving the understanding of the mechanisms of such losses. In turn, this increased understanding has led to the discovery of some drugs that show promise of counteracting the losses. Most of the knowledge about the neurotransmitters involved in these diseases has also been derived from studies of the brains and nervous systems of animals.

Primates are phylogenetically closer to humans than are other mammals. Their behavioral capabilities are in keeping with the greater development and complexity of their brains. Primates also have age-related decrements in memory function. Generally, memory impairment with advancing age first appears as a failure of immediate memory, the recall of events that have just occurred. Transmitter chemicals of the α-adrenergic class, like clonidine, were first found to improve memory performance in macaques and aged rodents. Clonidine has now also proved effective in improving the memory of patients with Korsakoff's syndrome. Those findings suggest a new approach to the treatment of patients with memory disorders, and they have provided a new option for clinical trials with patients suffering from Alzheimer's disease (Arnsten and Goldman-Rakic, 1985).

Pain is a common symptom of disease in humans and animals. It is important that medical science develop more effective methods of pain management than are now available. Much pharmacological research has focused on the production of drugs with potent analgesic properties, and much research on pain—particularly that concerned with analgesics, acupuncture efficacy, hypnosis, and so on—has been carried out on human subjects for over a century. Research using animals is necessary, however, if unsolved problems are to be adequately addressed.

Although many experiments that study pain must involve pain for the animal, researchers have developed methods that are as humane as possible within the context of the experiment. For example, the slightest reflex movement of the tail of a rat or mouse is objective evidence that a noxious stimulus applied to the skin of the tail has attained threshold intensity. Reflex behavior, such as the tail-flick, is a useful index of the comparative effectiveness of analgesics, as well as of the effects of manipulating chemical messengers in the central pain pathways (Willis, 1985).

The understanding of intrinsic brain mechanisms of pain and its modification will require the use of modern techniques for cell marking and pathway tracing, immunocytochemical and microphysiological methods, and sophisticated behavioral studies. Paradoxically, many investigations of pain can be explored in anesthetized animals. Thanks to psychophysical studies in humans that were replicated in animals, neuroscientists have been able to trace the nerve fibers from skin, muscle, and internal organs that are specific carriers of ''pain signals.'' With such a powerful handle on the input end of the pain system, the passage and transformation of pain signals can be explored in complex neuronal organizations in anesthetized animals. It is also possible to study the central systems that control the passage of pain signals to higher levels of the central nervous system. Finally, isolation and identification of the transmitters, structure, and other components of the neurochemical machinery of the brain involved in pain perception and its modification can be elucidated (Willis, 1985).

Increasing recognition that behavioral factors play a significant role in many current health problems—for example, drugs and alcohol abuse, eating disorders, effects of stress, cardiovascular disease, and mental and psychiatric ailments—has led to the development of animal models for experimental and biological analysis as part of the emerging field of behavioral medicine (Hamburg et al., 1982).

• Other Benefits for Humans

The preceding examples provide a sampling of the contributions that research using animals has made to the improvement of human health and the acquisition of knowledge. Many others could be cited—for example, the development of medicinals such as the sulfonamides (Hubbard, 1976); the development of life-support systems for premature infants (Coalson et al., 1982; deLemos et al., 1985; Escobedo et al., 1982); and the increase in understanding of learning (Miller, 1985; Pavlov, 1927; Skinner, 1938; Thorndike, 1898), nonlinguistic communication (Gardner and Gardner, 1969; Romski et al., 1984), drug abuse (Deneau et al., 1969; National Institute of Drug Abuse, 1984; Seevers, 1968), and nervous system regeneration. Many examples of such benefits are also chronicled in publications such as those by Gay (1986), Leader and Stark (1987), and Paton (1984).

• Benefits for Animals

One might have the impression that animal research is conducted only with the aim of alleviating human suffering. The conduct of extensive research in veterinary schools and other institutions indicates that that is not the case. Most research on domestic farm animals is undertaken to increase the productivity and quality of animal products. Research is also undertaken to reduce the suffering and increase the overall well-being of animals, particularly companion animals. Examples include current research on Potomac fever in horses, the development of ivermectin to eradicate parasitic diseases in a variety of animals, and the development of vaccines for feline leukemia virus and canine parvovirus.

Research aimed at human illnesses has also had immeasurable benefits for animals. A host of immunizations and antibiotics have proven applicable to the therapy of animal diseases (Paton, 1984). Kidney transplantation, cardiovascular treatments, chemotherapeutics, and narcotics are widely applicable, as are the insights gained from genetic research (Gorman, 1988).

One example of the benefits of biomedical research for animals can be found in the propagation of endangered species. The ability to transfer embryos, eliminate parasitism, treat illnesses, and use anesthetic advances has improved the health and survival of many species. The knowledge gained from genetic studies has allowed appropriate management of species that are endangered or have disappeared in the wild. For example, the ability to identify the sex of birds has been essential in the management of the whooping crane and the California condor. Research into obstacles to successful breeding in captivity has markedly reduced the need for importation of many species, especially monkeys. For example, among nonhuman primate species used in research, there were 7,908 births in 1984 in the United States, compared with 2,198 in 1973 (Johnsen and Whitehair, 1986).

Animal research has resulted in enormous benefits for humans and animals. The searching and systematic methods of scientific inquiry have greatly reduced the incidence of human disease and have substantially increased life expectancy. Those results have come largely through experimental methods based in part on the use of animals, as illustrated by the many examples cited in this chapter.

At the same time, much obviously remains to be learned. Further studies in such areas as cancer, heart disease, diabetes, AIDS, dementias, and the development of vaccines and chemotherapeutic agents will continue to require the use of animals.

• Cite this Page National Research Council (US) and Institute of Medicine (US) Committee on the Use of Laboratory Animals in Biomedical and Behavioral Research. Use of Laboratory Animals in Biomedical and Behavioral Research. Washington (DC): National Academies Press (US); 1988. 3, Benefits Derived from the Use of Animals.
• PDF version of this title (664K)

In this Page

Recent activity.

• Benefits Derived from the Use of Animals - Use of Laboratory Animals in Biomedic... Benefits Derived from the Use of Animals - Use of Laboratory Animals in Biomedical and Behavioral Research

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

Connect with NLM

National Library of Medicine 8600 Rockville Pike Bethesda, MD 20894

Web Policies FOIA HHS Vulnerability Disclosure

Help Accessibility Careers