Animal testing: ethics, methods, and scientific applications

Animal Testing

Animal models are faulty indicators and barriers in the development of drugs. Using animal models for human therapeutic experiments is inappropriate, unethical and unreliable. With new, faster and more accurate testing methods available it is high time that this cruel practice of Vivisection is totally banned from pharmaceutical research.

Animal testing is a cruel, unethical practice that is conducted on a large scale in almost all countries of the world. Taylor K. et.al (2008) reported that each year more than 115 million animals are used as test subjects worldwide. Statistics further indicate that in the U.S. alone, every year more than 25 million animals including mice, dogs, chimpanzees, cats, etc. are subjected to painful and invariably fatal tests. [Stephanie Ernst, 2008] Analyses of animal studies over the last several years have shown that animal testing is largely irrelevant for human subjects. For instance, more than 11600 chemical substances have been proven to have anti-cancer properties in mice while not even one of them has similar effect in humans. Also, among the 32 drugs that are used in cancer treatment among humans none prove to be effective in mice. [DLRM] This gives us a fair indication of the different physiologies and the inappropriateness of animal testing. Still most countries routinely continue with animal testing purely to fulfill regulatory requirements. A brief overview and a discussion of the relevant facts would help better understand this important issue.

Animal Testing: A Review

A recent comprehensive review of animal and corresponding human tests has clearly revealed vast differences in responses between animals and humans to particular drugs. This review published by the journal of 'Alternatives to Animal Testing and Experimentation' (AATEX) that analyzed 20 animal and human studies reported only 2 cases where animal studies proved to be consistent with the human studies. [Andrew Knight, 2007] Another recent British study compared the treatment effects between animal models and human clinical trials for six different medical conditions. Out of these, only 2 animal studies had concordant results with Human clinical trials. Furthermore 2 of the studies had totally contradictory effects than indicated in the animal studies. [Pablo Perel et.al (, 2007)] Hence the validity of using animal models as an indicator for human outcomes stands largely mistaken.

One standing example of the dangers of relying on animal models for drug testing is the case of the drug Vioxx manufactured by Merck Laboratories. More than 80 million people worldwide used this drug in the treatment of arthritis. However, the drug which was found to have "heart protective effect' among mice proved to be carrying a high risk for causing heart attacks among humans. As Dr. John J. Pippin, M.D and chief advisor to the FDA stated, "the Vioxx animal testing debacle is not unique. Over the years, millions of patients have been exposed to harmful drugs, such as Rezulin and Baycol, that seemed safe in tests on mice, dogs, rats, monkeys, horses, and other animals." [ PCRM]

Animal Testing: Barrier to Drug Development

There is enough evidence to suggest that animal testing has in fact delayed the development of critical drugs. The delay in the manufacture of Protease inhibitors, one of the main class of drugs for HIV patients, is a case in point. Back in 1989, Merck, Sharpe, and Dohme (MSD) worked on a protease inhibitor drug but negative results from animal testing discouraged their work from going to the next stage of human testing. However, 4 years later the companies continued their research again and manufactured the drug Crixivan (a protease inhibitor) and this time chose to skip the animal testing phase. The result was amazing among HIV patients. As Mr. Shapiro, the former vice president of MSD, stated, "Animal tests were neither needed, nor used, to explore the ability of protease inhibitors to block the growth of the Aids virus…the target action was already well understood and could be evaluated before the clinical trials using computers, cell culture and biochemical assays." [Peter Tatchell]. Thus it is clear that animal models provide unreliable and often contradictory results for pharmaceutical research experiments and also delay the development of vital drugs that could potentially save millions of humans.

New Testing Methods

Advancements in biotechnology have drastically impacted our understanding of diseases and the development of appropriate pharmacological interventions. 'Science-Based Toxicology' (SBT) enables us to study toxicity at the cellular level. There is definitive hope that SBT