ORLANDO, FLA. — A growing number of Americans choose exotic animals as pets without knowing that even handling these unusual creatures may result in serious dermatologic diseases, Dr. Ted Rosen said at the annual meeting of the Florida Society of Dermatology and Dermatologic Surgery.
“Pets can cause significant difficulties,” said Dr. Rosen, a professor in the department of dermatology at Baylor College of Medicine in Houston.
About 60% of U.S. households own at least one pet. One million to 2 million of those homes harbor an exotic pet—exotics that can carry pathogens that result in human disease.
Dr. Rosen highlighted disease concerns associated with some of the more common exotic pets:
▸ Hedgehogs. About 40,000 hedgehogs live in U.S. homes. The most popular species fits in the palm of the hand. Hedgehogs have quills, are vicious, and eat cockroaches.
“The most important thing about hedgehogs is they carry a very specific subspecies of Trichophyton mentagrophytes that is incredibly inflammatory,” Dr. Rosen said. “It is absolutely, astonishingly horrible. You get this from contacting the hedgehog.”
Some people are allergic to hedgehogs. They may develop contact urticaria related to hypersensitivity to the animal's saliva. Hedgehogs spit on their quills. These little animals are associated with human salmonellosis, and they carry various mycobacteria.
▸ Chinchillas. About 80,000 households own chinchillas, which carry Microsporum gypseum and Trichophyton mentagrophytes associated with inflammatory tinea capitis. These animals also harbor Aspergillus niger. They are susceptible to infections with gram-negative pathogens.
▸ Iguanas. About 750,000 iguanas are in U.S. homes. They shed Salmonella associated with human salmonellosis. Iguanas carry Serratia marscens in their oral flora, which can cause cellulitis after a playful nip or bite. The cellulitis may be bullous and present similarly to streptococcus or staphylococcus infection. However, iguana-associated S. marscens inhibits the activity of many drugs and is resistant to cephalosporins. The drug of choice is a quinolone or trimethoprim-sulfamethoxazole. Compounding the problem is the fact that breeders administer broad-spectrum antibiotics to keep the flora down and alter the reptile's color.
Allergic reactions to iguanas include allergic rhinitis and urticaria.
▸ Flying squirrels. Flying squirrels carry Rickettsia prowazeki, which is associated with typhus fever. The pet's owner can inhale the bacteria. Symptoms include fever; an extensive, nonspecific, blanching erythema eruption; headache; nausea and vomiting; myalgia; and photophobia.
Flying squirrels also carry unusual species of Staphylococcus that can be transmitted to people through wounds or small cuts. The infections are not easily treated and can cause sepsis.
▸ Gerbils. More than a million of these animals live in the United States. In nature, they are a major reservoir of Leishmania and Giardia lamblia and S. aureus.
As pets, they harbor avian mites, often acquired at the pet store. The bird infects the gerbil, which in turn infects humans.
▸ Prairie dogs. These animals are now banned as pets in the United States, after an outbreak of monkeypox in humans last year. The prairie dogs likely acquired the infection from Gambian rats. Prairie dogs can also carry plague and tularemia.
▸ Cockatoos and macaws. These birds are natural hosts for Cryptococcus neoformans, which may or may not make the pet sick. The bacteria can be transmitted to humans, with immunosuppressed patients at greatest risk. One of Dr. Rosen's patients died from a C. neoformans infection that he picked up from his pet cockatoo.