AIDS: The Centers for Disease Control and Prevention (CDC) states that there is no evidence that dogs, cats or non-primate animals can contract the human immunodeficiency virus (HIV) or transmit it to human beings. When the immune system is suppressed through disease, age, or medical treatments, a person becomes more vulnerable to infections. Pets Are Wonderful Support (PAWS) has developed guidelines for having pets. Proper pet selection, proper pet care and good personal hygiene of the owner can eliminate almost any possible risk a pet poses. New pets pose more of a health risk because health history and vaccination records are usually not known. Adult pets are often safer, and are less likely to be involved in playful activities that include biting and scratching. There is a slim chance of contracting toxoplasmosis from cats, but certain precautions can minimize risk. Annual veterinarian examinations are recommended to keep vaccinations current. The CDC does not recommend keeping a cat with feline leukemia virus or feline immunodeficiency virus since these diseases can make the cat more susceptible to other illnesses which can be passed on to a person with a compromised immune system. Turtles and birds are not recommended since they may harbor diseases. Several services are available to pet owners and are listed in the article.