Pet allergy is an allergic reaction to proteins found not only in the
animals' fur or hair but also in saliva, urine, mucous, and hair roots
and in the dander sloughed from the animals' skin. Thus, the
widespread idea that "hypoallergenic pets" are those that have less
hair or shed less is a myth.
Most often, pet allergy is triggered by exposure to the dead flakes of
skin (dander) a pet sheds. Any animal with fur can be a source of pet
allergy, but pet allergies are most commonly associated with cats,
dogs, rodents and horses.
Some dog breeds have been promoted as hypoallergenic because they do
not shed their hair, shed very little, or have the same pH as human
hair. However, no canine is known to be completely non-allergenic.
Some cat breeds, especially females are likely to have low levels of
Fel d 1, the main allergenic protein.
There is only one known hypoallergenic horse breed. The Bashkir Curly
horse has a uniquely textured coat that lacks the protein (present in
all other horse fur) believed to be the source of allergic reactions