By Joshua Place, DVM

Scientists, though experts on their specific area of study, may not be familiar with the quirks of the animals they use as their models. Understanding reproduction, complex medical treatments, and providing the appropriate environmental enrichment of an animal model in a way that minimally impacts study results is a crucial part of study design. Furthermore, despite the research benefits, animal testing is highly stigmatized due to concerns about humane animal treatment. In response to these unique challenges, veterinarians are involved in every stage of animal research projects, supporting animal welfare, administering medical care, and providing expert advice on enrichment and animal behavior that enriches both the researcher and the animal experience.

As a veterinary resident in the department of comparative medicine at Hershey Medical Center, I get to work with brilliant scientists engaged in cutting-edge research and consult with them on how to best care for their animals. I still treat diseases and provide medical advice, but I have traded the general practice exam room for the laboratory, and I love every minute of it!

You can think of us veterinarians “whole animal biologists” who receive training in veterinary school on the unique anatomical and physiological characteristics of a broad variety of species. Some veterinarians combine this medical training with a focus on biomedical science and animal research law to become unique specialists known as laboratory animal veterinarians.

The history of my unique specialty was not a straightforward path. In 1915, the Mayo clinic hired its first veterinarian, Dr. Simon Brimhall.¹ Dr. Brimhall’s role there resembled what laboratory animal veterinarians do today – providing veterinary care to research animals, managing animal husbandry and breeding colonies, studying animal diseases, and collaborating on biomedical research. Although Dr. Brimhall made many important contributions to his unique field of medicine, there were still only a very small number of veterinarians working in laboratory animal medicine until the 1940s.

In 1944, Congress passed the Public Health Service Act² which dramatically increased the funding to the National Institutes of Health (NIH). As  programs funded by the NIH grew, the demand for competent research veterinarians exploded¹, and a group of veterinarians formed the third ever veterinary specialty to be recognized, The American Board of Laboratory Animal Medicine³. (They switched it to “college” at some point and it’s now known as ACLAM – no affiliation with clams, though I bet we could figure out how to care for them!)

Following the creation of ACLAM, additional laws were passed, including The Animal Welfare Act of 1966 and the Health Research Extension Act of 1985, which required humane standards for research animals to be met by every government funded institution. In 1996, the National Research Council published the first edition of the Guide for the Care and Use of Laboratory Animals. This text included extensive specifications for every aspect of laboratory animal care, from sanitation and recordkeeping, to housing requirements and veterinary care. Using these guidelines, laboratory animal vets ensure that biomedical research projects comply with animal welfare laws by providing proper husbandry, enrichment, and veterinary care to animals involved.

Laboratory animals performing “species specific behaviors” are important indicators of animal welfare. For example, mice like to dig and burrow, and pigs like to root with their snout – to encourage these behaviors, we design small mouse homes, and pig balls, or make little cardboard toys for rats to shred (Figures 1-2). Laboratory veterinarians even design enrichment for less common laboratory animals like electric eels, or woodchucks! As we learn and design research projects exploring laboratory animal care, we publish them in journals to keep our passionate community informed about the latest in animal welfare ^4,5,6.

In addition to happier animals, proper animal enrichment benefits biomedical research. A healthy, non-stressed mouse is a much better experimental model than a mouse that experiences anxiety or boredom. Lack of proper animal husbandry or enrichment may lead to repetitive, functionless, “stereotypical behaviors,”  which in mice may include aimless jumping, chewing on wire bars, or circling. These behaviors may confound the research in question by altering physiologic states and behavioral tests. If all of the research animals in a facility are relaxed and living their best lives, the variability between studies shrinks dramatically, the quality of the scientific data increases, the scientists are thrilled, and the mice benefit from excellent welfare–a win-win for everyone!

Every animal study, in every facility, has been reviewed by a laboratory animal veterinarian. We provide researchers with guidance on medications, techniques, and ways to minimize pain and distress in the animals who are moving the frontiers of science forward. We train research staff on how to appropriately handle and care for the animals in their lab, and we are passionate about animal enrichment – which is one of my favorite aspects of my job.

Facilities that conduct animal research have many different ways to ensure that it is done humanely. Institutional Animal Care and Use Committees are made up of scientists, members of the public and veterinarians, and work carefully to review each study performed at their facility. Everyone involved in animal research strives to implement a principle called the “3 R’s”, created by scientists Russel and Burch and published in their book, the Principles of Humane Experimental Technique⁷. Briefly, the three R’s stand for “Replacement”–avoiding the use of animals when possible, “Reduction” – minimizing the number of animals used, and “Refinement” – minimizing the pain, suffering, or distress that research animals may experience.

I anticipate the day when animals are no longer necessary to advance biomedical research, but for now, we rely on them for life-saving medications, treatments, and discoveries. Until that day comes, I will be devoting my life to keeping research animals healthy and happy, and working with researchers to educate them about these amazing co-contributors to science.

TL:DR

• Animal research is an unfortunate but necessary part of biomedical advancements today.
• Laboratory Animal Veterinarians are a unique subspecialty of professionals poised to offer expert advice on research animal welfare, medical care, and enrichment.
• Biomedical research benefits greatly from the continued involvement of veterinarians–a healthy, non-stressed animal maximizes research value, minimizing the number of animals who sacrifice their life for science.

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References

1: Wolfle, Thomas L. “50 years of the Institute for Laboratory Animal Research (ILAR): 1953-2003.” ILAR journal 44.4 (2003): 324-337.

2: https://www.cancer.gov/about-nci/overview/history/public-health-service-act

3: https://www.aclam.org/about

4: Coda, Kathleen A., Jeffrey D. Fortman, and Kelly D. García. “Behavioral effects of cage size and environmental enrichment in New Zealand White rabbits.” Journal of the American Association for Laboratory Animal Science 59.4 (2020): 356-364.

5: Peveler, Jessica L., et al. “Effects of various commercially available enrichment options on handling and chronic stress markers in female ICR mice.” Journal of the American Association for Laboratory Animal Science 58.2 (2019): 119-125.

6: Backus, Brittany L., Mhairi A. Sutherland, and Tiffanie A. Brooks. “Relationship between environmental enrichment and the response to novelty in laboratory-housed pigs.” Journal of the American Association for Laboratory Animal Science 56.6 (2017): 735-741.

7: Russell, William Moy Stratton, and Rex Leonard Burch. The principles of humane experimental technique. Methuen, 1959.