Hairballs are common in cats, who are fastidious groomers. Loose and dead hair is swallowed and normally passes through the digestive tract. Some cat hair may collect in the stomach, especially if your cat has long hair. The hair irritates the sensitive lining of the stomach, and the cat will almost certainly regurgitate it while following the cat rule: back up while doing so, so the mess is as long as the human foot.

Hacking up a hairball once or twice a month or so is normal, but if it happens more often than that a visit to the vet may be in order. Hair may come up when the cat vomits, but you shouldn’t automatically assume that the hairball is the cause of the vomiting. If your cat is coughing while expelling a hairball, or your cat coughs with no resulting hairball, these can be signs of a more serious cat health condition that may need veterinary attention.

You can help your cat avoid hairball retching by combing her fur daily. Brushes are not as effective in removing loose hair; they simply smooth the surface of your cat's coat. Use a flea comb or fine toothed comb on a short-haired cat, or a wide-toothed comb on a fluffy cat. A “petting glove,” which looks like a mitten with a nubby rubber surface on the palm, also works well to remove loose hair.

A time-honored cat hairball remedy is to feed your cat a small amount of petroleum jelly regularly to help the hair slide through the digestive system. Smear a small amount on the cat’s paw, on the leg behind the elbow, or any other place she will find easy to lick off. Hairball treats work on the same principle but use mineral oil instead of petroleum jelly, and may have a laxative effect. Edible oils such as fish oil or flax seed oil will be absorbed by the intestines and may not do the job as effectively.

Adding fiber to your cat’s diet may also help push hair through the digestive tract, but cats do not require a lot of fiber in their diet and this remedy will add bulk to the cat’s stool, increasing the litter box mess.

Your cat may vomit if she has eaten something that didn’t agree with her, eaten too much or too quickly, eaten grass, rodents, lizards or other foreign substances, ingested a toxic substance, or have a gastrointestinal illness or other underlying disease. If your cat or kitten vomits once and then goes about her business as usual, eating, playing, and with regular toilet habits, there is probably no cause for alarm.

Vomiting in cats is cause for concern if it is chronic, or begins suddenly and is accompanied by blood in the vomit, diarrhea, lethargy, dehydration, loss of appetite, or any other unusual changes in her activity level or behavior. Your cat may have a feline gastrointestinal disorder, or the vomiting may be a secondary symptom of a more serious disease such as cancer, infectious disease, kidney failure, or diabetes. Consult a veterinarian who will give your cat a thorough physical examination, consider her medical history, and may order lab tests to determine the condition of your cat’s health and order any necessary treatments.