July 12, 2011 -- If you are thinking about adopting a dog and someone in your household suffers from pet allergies, you may have been told that certain breeds, including the Portuguese water dog made famous when it was adopted by the Obamas, are less likely to cause symptoms.
But this may be just a myth, a study suggests.
In the study, owners of poodles, schnauzers, and even Portuguese water dogs, widely promoted as hypoallergenic, have the same amount of a dog allergen known as "Can f 1" in their homes as owners of dogs not typically billed as hypoallergenic.
Can f 1 is formally known as canis familiaris allergen 1.
The study is published online in the American Journal of Rhinology and Allergy.
Researchers collected dust samples from 173 homes taken one month after a newborn was brought home. The samples were collected from the carpet or floor in the baby's bedroom.
Data were analyzed from homes with one dog only. The study included 60 dog breeds, 11 of which are often promoted as hypoallergenic.
The researchers found that 94.2% of homes showed detectable levels of the allergen, and there were no significant differences between breeds.
Adopting a Dog if You Have a Pet Allergy
The new findings don't mean people with allergies can't or shouldn't adopt dogs.
"Individuals need to work with a board-certified allergist on a case-by-case basis to determine which is the best dog for them," says study researcher Ganesa R. Wegienka, PhD, an epidemiologist at Henry Ford Health System in Detroit.
Rohit Katial, MD, an allergist at National Jewish Health in Denver, says the new study proves what he and others have been saying for a long time. "There is really no statistical difference in "hypoallergenic" dogs and others as far as allergen levels in the home."
"The allergen comes out of a dog's saliva and their pelt, and the hair is just a carrier as dogs lick themselves," he says.
If someone with pet allergies wants a dog or has a dog, "keep the dog out of bedroom and wash it frequently to get rid of the allergens," Katial says.
High-efficiency particulate air (HEPA) filters can remove almost all of the animal dander in the air, and may be a worthwhile investment, he says. Some HEPA filters can be attached to the furnace and may be efficient enough to clean the air in the entire house.
The American Kennel Club lists poodles, schnauzers and Portuguese water dogs as "hypoallergenic candidates" on its web site.
Christina Duffney-Carey, a spokeswoman for the American Kennel Club, says that no dog is 100% hypoallergenic, but there are breeds that have consistent and predictable coats.
"We recommend that if you do suffer from allergies, visit a breeder or someone you know with the type of dog to make sure it is the right fit," she says.