Sleeping With Dogs, Cats Linked to Disease, Infections, Parasites
Daniel J. DeNoon
WebMD Health News
Latest Infectious Disease News
Reviewed By Laura J. Martin, MD
In the U.S, surveys indicate that up to 56% of dog owners and 62% of cat fanciers regularly fall asleep with their pets in their bed. Reports from the U.K., Netherlands, France, and Japan suggest that this isn't a peculiarly American quirk.
But those cuddly pets harbor some icky germs, worms, and cooties, note Bruno B. Chomel, DVM, PhD, of the University of California, Davis, and Ben Sun, DVM, of the California Department of Health.
"Sharing our resting hours with our pets may be a source of psychological comfort, but ... sharing is also associated with risks," they write in the current issue of the CDC journal Emerging Infectious Diseases.
It's not just small animals. Chomel and Sun note that a survey recently reported by WebMD showed that 62% of small dogs, 41% of medium-sized dogs, and 32% of large dogs sleep in their humans' beds.
So what do these bed pets bring to our beds?
Humans get bubonic plague from fleas. Chomel and Sun recount various cases of plague linked to sleeping with cats. These include a 9-year-old boy from Arizona who slept with his sick cat.
And a 2008 study of plague survivors found that 44% of them slept with their pet dog, while only 10% of matched comparison subjects slept with their pets. This dog-in-bed plague risk remained significant even after the study authors took into account a large number of other factors.
This last factoid is troubling because dogs -- unlike cats -- can carry plague fleas without showing symptoms of the disease.
Chagas disease is a potentially fatal illness caused by a protozoan parasite. It's usually spread by the "kissing bugs" and other blood-sucking bugs.
But one study from Argentina suggests that people who own dogs and cats are at increased risk of the dread disease -- and that infection rates are significantly higher for those who sleep with their pets.
While Chagas disease is uncommon in the U.S., some experts worry that it is working its way northward through Mexico.
As the name implies, cat scratch disease is transmitted by being scratched by cats that harbor fleas infected with disease-causing bacteria. But being licked by a cat can also spread the disease.
In a Connecticut study of risk factors for cat scratch disease, patients were more likely than matched comparison subjects to have been scratched or licked by a kitten -- or to have slept with one.
The multidrug-resistant strain of strep known as MRSA rapidly is becoming widespread in the U.S. Humans can carry the bug in their noses -- and so can dogs.
Chomel and Sun recount the case of a couple that kept getting MRSA infections over and over again. Finally, doctors learned that their dog slept in their bed and licked their faces. Tests of the dog were positive for MRSA. And once the dog was rid of the germ, the couple stopped getting MRSA infections.
Other Bacterial Infections
Contrary to popular belief, the mouths of dogs and cats are not sterile. There are several bacteria that live in the mouths of carnivorous animals. Humans, particularly those with impaired or immature immune systems, can become infected.
Chomel and Sun describe one case of meningitis linked to a pet dog that often licked a baby's face.
Dogs often carry hookworms and roundworms. They can also carry protozoan parasites. These parasites, or their eggs, can sometimes be found on a pet's fur.
What You Should Do
It's relatively rare to get any of these infections from sleeping with a pet. But as Chomel and Sun show, it does happen.
They recommend that pets get regular veterinary examinations and vaccinations.
Because young children are at higher risk than adults, they recommend that small kids and adults with compromised immune systems avoid sleeping with, kissing, or even being licked by pets.
And they recommend that any area licked by a pet should immediately be washed with soap and water, especially if the pet licks an open wound.
"Our review suggests that persons, especially young children or immunocompromised persons, should be discouraged from sharing their bed with their pets or regularly kissing their pets," Chomel and Sun suggest.
SOURCES: Chomel, B.B. and Sun, B. Emerging Infectious Diseases, February 2011; published online ahead of print.
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