Diseases from Your Pets, Both Common and Exotic

SARS, monkeypox, and a host of diseases found their way into people from animals. Truth is, almost any critter can infect us.

So the huge growth in the popularity of exotic pets—snakes, lizards, monkeys, birds—is cause for concern.

"Fifteen years ago, you might have been the only person in your neighborhood with a ferret," says Karen L. Rosenthal, D.V.M., a veterinarian who focuses on special species medicine in Philadelphia. "These days, if you live in an apartment building, there's a good chance several people own ferrets."

Handle with care

An estimated 3 percent of U.S. homes house a reptile. You may like turtles, snakes, and lizards, but you should handle them with care. The CDC says reptiles infect about 70,000 people a year with the bacteria salmonella. In humans, salmonella can cause severe gastroenteritis and sepsis. Reptiles also can carry Edwardsiella tarda and Plesiomonas shigelloides, both of which also cause gastroenteritis in humans. Snakes can be carriers of Aeromonas shigelloides, a wormlike parasite, and Armillifer, a wormlike arthropod parasite, both of which can become parasites of humans.

Monkeys should "never be kept as pets," Dr. Rosenthal says. "Certain monkeys carry the herpes B virus, which is very serious and can be fatal to humans. Baby monkeys are cute, but they're not always clean and they can do a lot of damage."

Some birds carry serious infections, too, including Chlamydophila psittaci, which causes severe pneumonia; avian influenza; aspergillosis, a lung and sinus infection; Cryptococcus neoformans, which can cause meningitis; histoplasmosis, a lung infection; and blastomycosis, a lung infection.

Other pet diseases

Here are other animals and some of the diseases that they may pass on to humans:

• Cats. Cats can pass on toxoplasmosis, a parasitic infection that damages the developing fetus if a pregnant woman contracts it; sporotrichosis, a fungal disease of the skin and lymph nodes; rabies; cat-scratch disease; feline foamy retoviruses; Microsporum canis, which causes ringworm; Pasteurella multocida, which can cause a severe skin infection; Toxocara cati, a parasite that can cause loss of vision; Campylobacter jejuni, which causes severe gastroenteritis; and Nipah virus, which causes viral encephalitis.

• Rodents. Rodents can infect humans with lymphocytic choriomeningitis, a type of meningitis or encephalitis that can cause birth defects if a pregnant woman contracts it; hantavirus, which cause a fatal respiratory disease; salmonella; Trichophyton quinckeanum and T. mentagrophytes, which cause ringworm and other skin infections; Pasteurella multocida, which can cause a severe skin infection; Streptobacillus moniliformis or Spinillum minus, which causes rat-bite fever; Leptospira interrogans, which causes flu-like symptoms; Hymenolepis nana, a dwarf tapeworm; and Hymenolepsis diminuta, a rat tapeworm.

• Aquarium fish. Salt water and some freshwater fish tanks can contain Mycobacterium marinum, which can cause a skin infection. Exotic freshwater fish can carry Pseudomonas pseudomallei, which causes a lung infection.

• Prairie dogs. These animals can infect humans with monkeypox, a relative of smallpox.

• Guinea pigs and hamsters. These pets can carry salmonella; lymphocytic choriomeningitis; Yersinia pseudotuberculosis, which causes an infection that mimics appendicitis; Campylobacter; Trichophyton mentagrophytes; Hymenolepis nana; Trixacarus caviae, a parasitic skin infection found particularly in guinea pigs.

• Civets. Civets born abroad can carry the virus that causes severe acute respiratory syndrome (SARS). In 2003, the CDC banned the importation of all civets.

Reducing your risk

Still, your odds of infection from an exotic pet are low, more so if you take care. "If the animal was bred in the United States it's less likely to carry diseases that will make you ill," says E. Paul J. Gibbs, D.V.M., Ph.D., a virologist in Gainesville, Fla. "You shouldn't be afraid of going to someone's home that has such a pet, but don't handle it."

The CDC suggests you keep reptiles out of areas where you prepare or eat food. Make sinks and bathtubs used by people a reptile-free zone, too. After handling or being near reptiles and other animals, you can head off a lot of infections if you wash your hands thoroughly with warm water and soap.

"The main thing is to educate yourself before buying a pet of any type," says Dr. Rosenthal. "Most exotic pets have clubs you can contact. The members will tell you the good and the bad."