Animal dander is not the hair or fur of the animal, but is old skin scales which are constantly shed.
Older animals produce more dander than young ones because their skin is drier.
No, the primary cat allergen, Felis domesticus allergen I, is a glycoprotein found in the sebaceous glands of the cat's hair roots and in their sublingual salivary glands. It is also present in the urine of male cats. During grooming the allergen from the sebaceous glands is deposited with the saliva on the cat's fur. When it dries, it flakes off and is released into the air. Cat dander sticks to our clothing and personal belongings and is easily transported wherever we go.