There are several things that can be done to minimize your exposure to the infectious organisms that cause disease. First, make sure your pet receives all of the recommended vaccinations for its species. This will keep your pet from becoming infected with certain dangerous diseases and spreading them to other pets or humans. Second, if you are thinking of acquiring a rare or exotic pet, make sure you check all local and regional regulations to ensure that it is legal to keep the animal as a pet in your area; also, check with your veterinarian about any possible health risks that might be associated with the animal. And always make sure that any new animal receives a checkup from your veterinarian to ensure that it is healthy and disease-free.
It is always a good idea to minimize contact between wild animals and your pet. If your pet is housed outdoors, it is more likely to come into contact with wild animals or insects that can spread disease. Take reasonable precautions—for example, if you and your dog go for a walk in an area known to be associated with Lyme disease, use appropriate flea and tick preventives. Always check both yourself and your pet for ticks upon your return home. Avoid contact with droppings from other animals that could spread disease or parasites.
When your pet has an infectious disease, keep it separated from other pets and people in the household, if possible. Hands should always be thoroughly washed after any contact with the sick animal or its environment (bedding, toys, or food, for example). It may be necessary in some cases to thoroughly clean and sanitize the area, or even destroy some items such as bedding. Your veterinarian can provide appropriate guidelines, depending on the type of infection your pet has.
Also see professional content regarding prevention of zoonoses.