A hairball, also known as a trichobezoar, is a clump of fur that a pet, typically a cat, has coughed up or vomited. It is made up of the fur that a pet has ingested while grooming itself and is usually round in shape. The size of hairballs can vary greatly and they can be as small as a pea or as large as a tennis ball.

Hairballs are not usually a serious medical concern, but they can be a sign of an underlying health problem such as hair loss or fur mites. If your pet has been vomiting up hairballs more frequently than usual, it is important to take them to the vet for a check-up.

The best way to reduce the number of hairballs your pet produces is to groom them regularly. Brushing your pet's fur helps remove loose hair and prevents it from ending up in your pet's stomach. If your pet is prone to hairballs, there are also a number of special foods and supplements available that are designed to reduce the likelihood of your pet developing a hairball.

Hairballs can be an unpleasant surprise for pet owners, but they are usually nothing to worry about. With regular grooming and a good diet, you can help reduce the number of hairballs your pet produces. If your pet is having trouble with hairballs, however, it is important to take them to the vet for a check-up.