Veterinarians care for pets, livestock, sporting and laboratory animals, and protect humans against diseases carried by animals. Veterinarians diagnose medical problems, dress wounds, set broken bones, perform surgery, prescribe and administer medicines, and vaccinate animals against diseases. They also advise owners on care and breeding. Most veterinarians are in private practice. Some have a general practice, treating all kinds of animals. The majority, however,just treat small companion animals such as dogs, cats, and birds. Others treat both small and larger animals, and some treat only large animals, such as cattle and horses. Veterinarians in companion animal medicine provide services in 20,000 animal hospitals or clinics. Veterinarians for large animals treat and care for cattle, horses, sheep, and swine. They also advise ranchers and farmers on the care, breeding, and management of livestock. Others specialize in fish and poultry. Veterinarians contribute to human as well as health. A number of veterinarians engage in research, food safety inspection, or education. Some work with physicians and scientists on research to prevent and treat diseases in humans. Veterinarians are also in regulatory medicine or public health. Those who are livestock inspectors check animals for disease, advise owners on treatment, and may quarantine animals. Veterinarians who are meat inspectors examine slaughtering and processing plants, check live animals and carcasses for disease, and enforce government food purity as well as sanitation regulations. Some veterinarians care for zoo or aquarium animals or for laboratory animals. Veterinarians help prevent the outbreak and spread of animal diseases, some of which like rabies can be transmitted to humans, and perform autopsies on diseased animals. Some specialize in epidemiology or animal pathology to control diseases transmitted through food animals and to deal with problems of residues from herbicides, pesticides, and antibiotics in animals used for food.