Pets can be a wonderful source of fun, companionship and comfort. Unfortunately, a lack of knowledge about zoonoses -- diseases spread from animals to humans -- has led some providers to suggest that people with HIV should not own pets. While it is true that people with weakened immune systems are more susceptible to zoonoses, there is a lot that can be done to lower the risk, allowing most HIV-positive people to safely keep and care for pets. Patrick Sullivan, a veterinarian with a Ph.D. in comparative and experimental medicine who works at the U.S. Centers for Disease Control and Prevention (CDC) in Atlanta, recently gave a talk on this subject to providers at Harborview Medical Center.

In his presentation, Dr. Sullivan outlined some common diseases that pets can carry and how to avoid getting these infections from pets. He joked that his message could be summarized in three simple pieces of advice: "Wash your hands, cook your food, and don't play with feces." Another important point emphasized throughout the talk was the importance of advocating with veterinarians for prompt and aggressive care of pets, especially when they are ill.

The illnesses mentioned that pose a pet-to-human transmission risk were Bartonellosis (cat scratch disease), Campylobacteriosis, Cryptosporidiosis, Mycobacteriosis (MAC), Salmonellosis, and Toxoplasmosis. Dr. Sullivan noted that for most of these diseases, pets are not the most common source of infection. Most exposures to MAC, for instance, are atmospheric (from the environment), rather than from animals. Only 3% of salmonella exposure is from pets. The vast majority of this illness is from contact with raw or undercooked meat.

Toxoplasmosis is a disease, like many other opportunistic infections, that is present in the majority of the population. In fact 70% of people show signs of exposure to "toxo." Most cases of cerebral toxoplasmosis that occur in HIV-positive people are probably re-activations of existing infections and are not due to new exposures from animals. A recent study of over 400 HIV-positive people in Florida found that developing toxoplasmosis was independent of whether or not a person owned a pet.

While the risk of getting any of these infections from pets is small, it is important to take some common sense steps to reduce the chance of contracting any disease from your pets:

Choosing a Pet

• Avoid reptiles. Reptiles have a high rate of salmonella infection.

• Look for older, calmer cats and dogs. Kittens and puppies are more likely to have infections, and to bite or scratch people.

• Use caution when adopting pets from stressful or crowded environments.

• Consider having a friend with a strong immune system keep a new animal for a while before bringing it into your home.

• Look for healthy animals. Cats with FIV (feline immune deficiency virus) may be more susceptible to infections and be more contagious when ill.

Caring for Healthy Pets

• Wash hands after petting or playing with animals.

• Avoid all contact with pet feces. Have someone else (when possible) empty litter boxes daily.

• Watch what your animals eat. No raw meat, no mice, no feces

• Eliminate fleas. Some infections may be transmitted by fleas.

• Use caution and wear gloves when cleaning aquariums and fish bowls, or have someone with a strong immune system do it for you.

• Consider keeping pets indoors to limit their exposure to other animals or feces that may carry infections.

• Get regular veterinary check-ups and disease screenings for your pets, especially new animals.

What to Do if a Pet is Ill

• Again, avoid contact with feces and wash your hands frequently.

• Set up a support network of friends, family and kennels to care for pets with diarrhea.

• Pets with diarrhea should be seen by a veterinarian as soon as possible.

• It is important that veterinarians test a sick animal's feces to determine if there is an infection.

To conclude his talk, Dr. Sullivan presented encouraging data from the Multicenter AIDS Cohort Study (MACS) on the benefits of pet ownership for people with HIV. The study found that owning a pet decreased the chance that someone with HIV or AIDS would experience depression, especially for people without a lot of human support.

It is possible, and beneficial, for most people with HIV to safely own pets. Open and honest communication with your healthcare provider and veterinarian can help you live safely with your pets. For additional information about pet-ownership by people who are HIV-positive, check out the CDC's website at: http://www.cdc.gov/hiv/pubs/brochure/oi_pets.htm or call the AIDS Clearinghouse at (800) 458-5231.