As the name would suggest, hairballs are the result of hair that has been swallowed by your cat during grooming.
Usually the hair will pass through the cat's digestive system and out of the body via the feces, however, if enough hair is swallowed, it will build up in the stomach, causing a ball. Eventually, this causes irritation to the stomach, causing the cat to vomit the hairball back up. Quite often, all you will see is a long, wet tube of vomited fur on the floor. Once the hairball has been passed, your cat will be fine.
Long haired cats are more prone to developing hairballs, and they also may occur during times of heavy shedding as the weather warms up.
The goal in relieving hairballs is to assist the passage of the hairball via the use of lubricants.
Add a teaspoon of canned of boiled pumpkin to your cat's food once or twice a week. This adds fibre to the diet and assists with the passage of feces.
Once a week, smear 1/2-1 teaspoon petroleum jelly onto your cat's paw, this acts as a lubricant, helping the feces pass more easily.
Alternatively, add a teaspoon of butter or olive oil to your cat's food once or twice a week.
1/4 teaspoon of Metamucil can be added to your cat's food daily to help the hairball to pass out of your cat more easily.
Cats with ongoing problems with hairballs may benefit from a hairball-controlled diet or treats.
Daily grooming to remove loose hairs is also important, especially in long haired or older cats.
Never attempt to force oil (olive oil, mineral oil) into your cat's mouth as this can easily end up in the lungs and cause aspiration pneumonia. It is much safer to add oils to your cat's food, and if this doesn't work, try another method listed above.
When to see a vet:
Hairballs are usually more of an annoyance than anything else, but if they are not passed out of the stomach, they can cause a blockage.
Watch out for:
If you notice any of the above symptoms, seek veterinary attention immediately. An intestinal blockage is a medical emergency.