A hairball is a blob of fur that forms in a cat’s stomach due to the cat swallowing its own fur while grooming. When the hairball becomes too large the cat vomits it up. Frequent hairballs are not normal and if a cat is having a hairball more than once a month this is a sign of a minor concern.
Cats groom themselves a lot and their tongues are coated with barbs so if they get loose hair stuck to their tongue it is swallowed. The key to preventing hairballs is to prevent the cat from having too much loose hair.
One of the authors long haired cats
Cat owners should brush their cats every two days for short periods of time (think how often you brush your own hair). Even brushing a cat once a week will help reduce hairball problems. Some cats like being brushed more than others. A gentle slicker brush works well for removing loose hair.
Cats fed better quality cat food will also have a healthier skin and coat. A lot of cat foods use cheap filler, such as corn and by-products, which often result in increased shedding and as such more hairball problems. A good cat food uses real meat as the first ingredient and does not contain cheap fillers.
Stress also increases shedding in cats, and as such increases the formation of hairballs. In animal shelters cats are stressed and as such they have more hairballs, but in stressful homes this is a problem too.
Older cats tend to have more skin problems and digestion concerns as well and are more likely to have hairballs as a result.
A cat should never be punished for spitting up a hairball. Indoor only cats should be provided with some “cat grass” to help them vomit when needed to ease tummy problems as the result of having hair in the stomach.