Families all over are talking about the quest to pick the right dog for president-elect Barack Obama’s family. Because daughter Malia is allergic, there’s a lot of talk about the Obamas getting a “hypoallergenic” dog.

But one local allergy expert preaches caution.

“The current talk about ‘hypoallergenic’ dogs . . . can lead to negative outcomes if they perpetuate a myth and create unfounded expectations,” Dr. Alvin Sanico, medical director of the Asthma Sinus Allergy Program at Greater Baltimore Medical Center, wrote to me.

“The fact is that all dogs and cats produce allergens that can be found in their dander and saliva, regardless of their breed and the length of their hair, or lack thereof,” wrote Sanico, who is also an assistant professor of medicine at the Johns Hopkins Division of Allergy and Clinical Immunology. “Some may produce more - or less - allergens than others simply because of their individual nature. Based on this premise, it wouldn't really matter if the Obamas choose a "mutt" over the various breeds that pet pundits now suggest.”

For example, voters in an American Kennel Club poll suggested a poodle would be the best breed for the Obamas. But Sanico cites a study published in the journal Allergy that found levels of an allergenic protein can vary widely within the same breed, and that poodles, for example, can shed relatively high amounts of it. The study concluded there was really no such thing as a hypoallergenic breed.

So how is a family – “first” or otherwise – to choose a pet, if avoiding pets isn't an option? “Before the choice of a dog is finalized, a trial period would be advisable to test whether exposure (to the chosen dog) triggers significant symptoms,” Sanico writes. “Control of allergy and asthma need to be optimized and maintained with appropriate medications. Allergen immunotherapy may be considered, with the understanding that it would take several months before desensitization can be achieved. With the right strategy, the pet can provide joyful companionship instead of consternation.”