These consider some of the issues relating to the use of animals in biomedical research:
When polio first appeared around 1835, it rapidly paralysed and killed its victims. In 1908, a virus was suspected and scientists began working on a vaccine. They discovered the polio virus in human intestines as early as 1912, suggesting entrance through the digestive tract. However, because animal research indicated that monkeys contract polio nasally, and because scientists working on the vaccine ignored the human findings in favour of the animal findings, the development of an effective vaccine was postponed for decades (Sabin 1965; Parish 1968). In 1941, after conducting human autopsies, Dr. Albert Sabin found the virus confined to the gastrointestinal tract as had been documented nearly 30 years earlier. He noted that ‘(…) prevention was long delayed by the erroneous conception of the nature of the human disease based on misleading experimental models of the disease in monkeys.’ (Sabin 1984)
Animal research also significantly side-tracked the development of penicillin. In 1929, Alexander Fleming observed penicillin as it killed bacteria in a Petri dish. Intrigued, he administered the compound to bacteria-infected rabbits, hoping it would do the same thing. Because the penicillin was ineffective against the rabbits’ infection, Fleming set aside the drug for another decade. Years later, he administered the drug in desperation to a dying patient, for whom all other treatments had been ineffectual. The penicillin saved his patient’s life and the rest is history. Fleming later commented, ‘How fortunate we didn’t have these animal tests in the 1940s, for penicillin would probably never been granted a license, and possibly the whole field of antibiotics might never have been realised’ (Parke 1994).
Advocates of animal research often cite the development of insulin as an example of the value of animal research. While it is true that insulin obtained from animals saved the lives of many diabetics, animal research was not useful in investigating the cause of this disease. Physicians in the late 18th century first linked diabetes to changes in the pancreas seen at human autopsy. Although dogs, cats, and pigs became diabetic when their pancreases were removed, their symptoms led researchers to conjecture that diabetes was a liver disease, throwing diabetes research off track for decades. In 1922, scientists spoke out against the animal experiments (Roberts 1922), pointing out that human autopsy had in fact shown the pancreas to be the vital organ in diabetes, and that it was in vitro research that was responsible for the isolation of insulin.
The discovery of the DNA double helix, arguably the 20th century’s most important medical breakthrough, was thanks to non-animal technology and in vitro research. Similarly, we owe our ability to view the heart’s blood vessels to German urologist and Nobel prize winner, Werner Theodor Otto Forssmann. He had tried his procedure on rabbits but they had died. Fortunately Forssman distrusted his animal experiments and in the tradition of many physician scientists, experimented on himself instead. By sliding a catheter into his own arm and taking x-rays, he showed that a catheter could be threaded to the heart without problem. As a result doctors can now monitor blood vessels, detect problems and implement preventive measures.