Rabbit
Rabbits are the reason our dogs and cats can live with us in our houses. Louis Pasteur worked with rabbits to develop the first rabies vaccine which made it safe to bring pets into our homes. Rabbits have a similar anatomy and physiology to humans, especially their cardiovascular system, and are susceptible to the diseases that have human equivalents. Today they are needed for studies involving cancer, glaucoma, ear and eye infections, diabetes and emphysema.