Frequent grooming is another natural behavior of the cat. The feline tongue's prickly surface acts as a brush to remove loose hairs, parasites, and other foreign material from the coat. The saliva a cat transfers from its mouth to its coat contains proteins that may play a role in conditioning the hair.
Unfortunately, the saliva also contains a protein that causes an allergic reaction in some people. Allergists have recently learned that most of the nearly 10 per cent of people in the United States who are allergic to cats are sensitive to this protein in cat saliva. When these people are exposed to loose cat hairs in a room, they may come in contact with the protein and suffer an allergic reaction, such as sneezing, runny nose, or difficult breathing.