Animal dander is the protein found in dry skin flakes shed by furry and feathered animals.

Source: American Academy of Allergy, Asthma and ImmunologyAnimal dander is a potent asthma and allergy trigger that is found in both long- and short-haired furry & feathered animals
Animal dander is only one of the
animal allergens. Others include animal urine and saliva. Dander is the product of dry skin flakes that every animal sheds — by the thousands — on a daily basis. Animal dander can come from long- and- short-haired animals, and there is no animal with fur and feathers that doesn't shed dander. It's important to understand, though, that it is
not the pet's hair or feathers that acts as a trigger.
If you or your child have allergic asthma and come in to contact with pets — at home, at friends or families' houses or in school — then allergy and asthma symptoms can result. In fact, just being in an environment where an animal lives, even if they are not there at the same time as you, can be enough to set off asthma and allergy symptoms.
If animal dander (or other animal allergens) is one of your asthma/allergy triggers, then reviewing these tips on how to reduce animal allergen exposure will be helpful in controlling your asthma.