For years, scientists believed that the central physiological functions of circulation, respiration, and nervous system were common to all mammals. However, no species of animals have been identified which has the same absorption, distribution, metabolism, and excretion processes of drugs as humans. It is unlikely that such an animal species will ever be found. Despite this, there is a persisting opinion that animal research has made a significant contribution to the treatment of human diseases. This is not based on fact, as most of the research using animals is known to be wasted.
Dogs have always been found to be inconsistent predictors of toxic responses in humans. A study conducted, at the School of Pharmacy, University of Connecticut, as early as 1982 found that most derivatives of the drug Benzodiazepine, used in many common medicines, have a much smaller half-life in dogs as compared to humans. As these drugs are processed and metabolised much faster in dogs, results of tests conducted on dogs become irrelevant to predict the side effects or toxicology on humans.
Other new non-animal methods, have a number of benefits over testing on animals, particularly dogs — they save huge amounts of time and money, they provide more reliable results, the ethical concerns are minimal and the financial and practical implications of rearing animals etc. are much lower. There are benefits for all involved if a move is made away from animal testing, particularly laboratory testing of dogs.