Animal Testing in Medical Research: A Literature Review

This literature review examines the current studies on animal testing in medical research, including the benefits and drawbacks, history, and future of animal testing. The review focuses on articles published in the past seven years and evaluates the reliability and ethical considerations of animal experimentation.

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Research 2
Part 2
Literature Review
Introduction
Animal testing has played a significant function in medical research from antiquity up to today.
However, animal experimentation has been an issue of heated discussion both in the medical
field and from the proponents of animal welfare (Mak, Evaniew, & Ghert, 2014). Several studies
have been conducted to justify the need for the continual use of animal testing but with improved
care on the welfare of animals while others have shown evidence on the flaws of animal
experimentation. Arguments on the reliability of the animal testing and the provision of
appropriate models for human biology among others have been the arguments for and against
animal testing. Therefore, there is a need for a more in-depth review of the current studies to
ascertain whether there is still a place for animal testing in medical research. This review will
examine articles published in the past seven years to make the findings relevant to the current
practitioners in the medical field. The specific themes under focus include the benefits and
drawbacks of animal testing, history of animal testing and its state into the foreseeable future.
Akhtar (2015) conducted a study on the flaws and human harms of animal experimentation by
examining varied evidence for and against animal testing. Despite the existing evidence of the
limitations and unreliability of animal experimentations, the biomedical community are still
confident that they can be overcome. The three primary factors that undermine this confidence
include the differences between the animal models of sickness and human illnesses, the impacts
of the laboratory environment and other factors on the outcomes, and the variations in the
physiology and genetics of the species. These factors are critical and are likely to cause

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significant harms to humans through misleading safety studies, elimination of effective methods
among others.
The present status of animal testing in medical practice was evaluated by Kehinde (2013) by
assessing the current and potential advancements in the medical field in animal testing and to
determine whether there are still valid scientific benefits for using laboratory animals. Despite
the existing debate against the use of laboratory animals, the benefits far outweigh the
drawbacks, thus justifying the current use of animal testing. It is economical and faster than
clinical trials, consists of minimal ethical constraints than clinical trials, it is a basis for further
research into some aspects of the disease. These findings agree with those of Akhtar (2015) who
also found that animal experimentation may be used into the foreseeable future due to its
significant benefits that outweigh the drawbacks.
Franco (2013) also provided a historical perspective of animal testing in biomedical research.
Scepticism towards animal testing began as early as the 17th century on experiments such as
vivisection. Since then the critics and advocates of animal experimentation have been involved in
a heated debate to the present day. By the 20th century, there was an upsurge of animal liberation
and a call for more human science. It is likely that the historical controversy on animal
experimentation will continue to exist into the foreseeable future but with continuous
development on the improvement of the wellbeing of experimental animals.
The major arguments for the continuous use of non-human primates are reliant on different
ethical frameworks. Therefore, to ascertain the validity of these arguments, the frameworks
which form the basis of the arguments should be assessed. This was the objective of Carvalho,
Gaspar, Knight and Vicente (2018). The authors examined the present ethical frameworks that
provide guidelines for both human and non-human experiments namely: deontology and

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utilitarianism respectively. The researchers found out that the utilitarian framework is not
adequate for its role because it's not possible to precisely predict the advantages, and the harm
inflicted on the animals is so much. These findings are contrary to those of Kehinde (2013) and
Akhtar (2015) who advocate for animal testing by arguing that they are more reliable,
economical and less risky than control trials.
The recent development in neuroscience depicts high similarity in the various functionalities of
primates such as dogs and human beings. Dogs are capable of positive emotions or empathy.
Moreover, the functioning of the caudate nucleus (responsible for pleasure and emotion), the
voice area in the canine brain, and an area in the temporal cortex of dogs useful in face
recognition in dogs are similar to that of humans. Therefore, this makes it unjustifiable to use
dogs in invasive and toxicity testing in the laboratory (Bailey & Pereira, 2018).
The continuing debate on whether to continue, eliminate or partially adopt animal
experimentation has led to confusion in pharmacology education and research. Badyal and Desai
(2014) sought to address this changing scenario by examining the evolution of the use of animals
for laboratory research in education and how it has been affected by the advocates for animal
welfare and government regulations. Critics have condemned how animals used in toxicity and
dermatological studies are handled. On the other side, scientists promote the appropriate use of
animal testing because it allows adequate room for exploration. Animals can not be eliminated
from research, but there should be an emphasis on the adherence to the existing regulations.
Morgan et al. (2013) underscore the importance of the use of laboratory animals for research
only but under special consideration because the animal disease models will be the most
appropriate for experimental studies into certain toxicities. The author argues that drug
development and safety evaluation is most effective in using animal testing. Existing guidelines

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such as those provided by the FDA draft permit the use of animal studies as long as efficacy data
obtained from animal studies have been approved and that its impossible to carry out human
clinical trials to ascertain the efficacy (Kilkenny, Browne, Cuthill, Emerson, & Altman, 2012).
Similar conclusions were arrived at by Nurunnabi, Afroz, and Alam (2013) who evaluated the
ethical debate on animal research. The increasing agitation and awareness have made the
majority of the researchers and relevant institutions to ensure that animal testing is only carried
out where necessary and should cause the least suffering to animals.
Similarly, Mann, Sun, and Hermerén (2019) posit that there is no problem in the use of animals
in laboratory studies as long as the changes caused in the animal are morally relevant to the
degree that they do not negatively affect the moral status of an animal. As a result, the study
recommends an ethical assessment framework of chimeric animal research as a useful tool for
bringing appropriate considerations of ethics in animal research. There are instances in which
only the use of animal models can produce effective and reliable results. For instance, Denayer,
Stöhr, and Van Roy (2014) and Martić-Kehl, Schibli, & Schubiger (2012) found out that after
considerations of the efficacy and endpoints in translational medicine, animal models were most
appropriate in combination with other emerging alternative methods. Veazey (2013) examined
the utility and relevance of animal models for efficacy and safety in the prevention and
protection from HIV transmission. The author found out that human clinical trials failed whereas
humanized mouse models produced reliable results, and where the safest and most effective even
in conducting future human trials.
Conclusion
The debate on whether animal experimentation is still relevant in medical research is a subject of
contention between the critiques and advocates. The common argument of the critiques is that

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the use of animals is unreliable and unethical because the animals are subjected to pain, stress
and the effects may be permanent. Moreover, there is a wide variation in the animal models of
sickness and human illnesses, the impacts of the laboratory environment and other factors on the
outcomes, and the variations in the physiology and genetics of the species. On the other hand, the
advocates of animal experimentation contend that there are experiments in which it would be
impossible to use human clinical trials and that it would be more unethical to use humans. Thus,
the solution would be to use animals under the provided ethical guidance and when it is
necessary but not to eliminate animal testing from the medical field.

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References
Akhtar A. (2015). The flaws and human harms of animal experimentation. Cambridge quarterly
of healthcare ethics : CQ : the international journal of healthcare ethics
committees, 24(4), 407–419. doi:10.1017/S0963180115000079.
Badyal, D. K., & Desai, C. (2014). Animal use in pharmacology education and research: the
changing scenario. Indian journal of pharmacology, 46(3), 257–265. doi:10.4103/0253-
7613.132153
Bailey, J., & Pereira, S. (2018). Advances in neuroscience imply that harmful experiments in
dogs are unethical. Journal of medical ethics, 44(1), 47-52.
Carvalho, C., Gaspar, A., Knight, A., & Vicente, L. (2018). Ethical and Scientific Pitfalls
Concerning Laboratory Research with Non-Human Primates, and Possible
Solutions. Animals :
an open access journal from MDPI, 9(1), 12. doi:10.3390/ani9010012
Denayer, T., Stöhr, T., & Van Roy, M. (2014). Animal models in translational medicine:
Validation and prediction. New Horizons in Translational Medicine, 2(1), 5-11.
Franco, N. (2013). Animal experiments in biomedical research: a historical
perspective. Animals, 3(1), 238-273.
Kehinde E. O. (2013). They see a rat, we seek a cure for diseases: the current status of animal

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experimentation in medical practice. Medical principles and practice : international
journal of the Kuwait University, Health Science Centre, 22 Suppl 1(Suppl 1), 52–61.
doi:10.1159/000355504.
Kilkenny, C., Browne, W. J., Cuthill, I. C., Emerson, M., & Altman, D. G. (2012). Improving
bioscience research reporting: the ARRIVE guidelines for reporting animal
research. Osteoarthritis and cartilage, 20(4), 256-260.
Mak, I. W., Evaniew, N., & Ghert, M. (2014). Lost in translation: animal models and clinical
trials in cancer treatment. American journal of translational research, 6(2), 114–118.
Mann, S. P., Sun, R., & Hermerén, G. (2019). A framework for the ethical assessment of
chimeric animal research involving human neural tissue. BMC medical ethics, 20(1), 10.
Martić-Kehl, M. I., Schibli, R., & Schubiger, P. A. (2012). Can animal data predict human
outcome? Problems and pitfalls of translational animal research.
Morgan, S. J., Elangbam, C. S., Berens, S., Janovitz, E., Vitsky, A., Zabka, T., & Conour, L.
(2013). Use of animal models of human disease for nonclinical safety assessment of
novel pharmaceuticals. Toxicologic pathology, 41(3), 508-518.
Nurunnabi, A. S. M., Afroz, R. D., & Alam, S. N. (2013). Ethical Debate on Animal
Research. Bangladesh Journal of Bioethics, 4(3), 11-18.
Veazey R. S. (2013). Animal models for microbicide safety and efficacy testing. Current
opinion