A hairball is exactly what it sounds like: a small accumulation of hair in your cat’s stomach or small intestine collected and swallowed during your cat’s auto-grooming sessions. When the cat can’t excrete the hair a ball forms, which must be vomited up or it will obstruct the cat’s intestinal tract.

Signs of hairballs include gagging, vomiting, weight loss or loss of appetite, and constipation. Most cats are able to eventually cough up the ball, but frequent hairballs can be dangerous. If your cat is prone to hairballs, experts suggest increasing the motility of the digestive tract with mild cat laxatives (human products can be too strong, and homemade products can create other digestive problems). Regularly brushing your cat -- daily for long-haired cats, weekly for short-haired -- can lessen the amount of hair the cat ingests. Also, some dry cat foods are made with an anti-hairball formula. Some vets warn that hairballs can actually be a warning sign. According to experts, if cats continuously throw up hairballs, it's an indication that owners are not spending enough time grooming the cat.