Why Is My Cat Vomiting?

Cat vomiting is extremely common, but there's a widespread misconception that it's "just what cats do." While an occasional hairball or a rare episode of vomiting from eating too fast can be normal, regular vomiting is not. A cat who vomits weekly or more often has a medical problem.

Distinguish between vomiting and regurgitation. Vomiting involves active abdominal contracting and produces partially digested food or bile. Regurgitation is passive and produces undigested food in a tubular shape right after eating. The distinction matters for diagnosis.

Hairballs are the most culturally accepted cause, but if your cat has hairballs more than once or twice a month, there may be an underlying issue — excessive grooming from skin disease, stress, or GI motility problems that prevent hair from passing normally through the digestive tract.

Chronic vomiting (ongoing for weeks to months) is most commonly caused by inflammatory bowel disease (IBD), food allergies, or hyperthyroidism in older cats. Less common but serious causes include intestinal lymphoma (a form of cancer), pancreatitis, and liver or kidney disease.

Acute sudden-onset vomiting is more often caused by dietary indiscretion, foreign body ingestion (string, ribbon, and hair ties are classic), toxin exposure, or infections. Cats who chew on plants should be checked — lilies are fatally toxic to cats.