There are vast numbers of rabbit breeds on earth, and people keep them for different purposes. Rabbits provide meat, fur, and they make perfect family companions, because actually they are no less trainable than cats. All rabbits are herbivores, and their diets should include alfalfa, lettuce, clover, grass and so forth. Rabbits cannot vomit, and this frequently results in the formation of hairballs in the stomach and ensuing digestion problems.