Cats get a lot of pleasure from grooming and will spend hours luxuriating in self-engrossed cat-baths. Not surprisingly, they swallow a lot of hair. Fur doesn't digest well, so it often stays in the stomach until, with a lot of noisy retching, it is propelled back up again.
Hair balls aren't pleasant for cats or for people, but these fur-and-fluid concoctions aren't usually a problem. "It's the hair that doesn't get thrown up that is the biggest worry," says Joanne Hibbs, D.V.M., a veterinarian in private practice in Powell, Tennessee. Hair in the stomach often passes into the intestine, where it can create a blockage that requires surgery to remove.
Most cats don't have any trouble coughing up hair balls. If the wad of fur is too large, however, it can get stuck on the way up, possibly blocking the flow of air. It is normal for cats to make loud, dramatic noises when vomiting up hair balls. But if your cat is also pawing frantically at her face, her gums are turning blue, or she passes out, get her to the vet emergency room immediately, says Dr. Hibbs.