ABSTRACT
The use of animals with medical and biological objectives has been practiced for centuries. Areas of biomedical research, such as pharmacology, physiology, and toxicology, have based their progress in experiments carried out mainly in animal models or in the accurate observations of spontaneous phenomena in animals. Advances in human health conditions are, in part, the result of the knowledge of biological processes, which were rst understood in animal models. Laboratory animals have also contributed in the development of vaccines, methodology for the diagnosis of different illnesses, identication of pharmacological target cells or molecules for new pharmaceutical products, organ transplantation, grafts, and much more.
