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Cornell Feline Health Center

Supporting Cat Health with Information and Health Studies.


Even the healthiest cat is apt to vomit now and then. In many cases, there’s nothing to be concerned about—except the cost and effort required to clean up the resulting stain on, say, a brand-new oriental rug. But if the otherwise fastidious little animal frequently gags and throws up whatever it has recently ingested, there is reason for concern, and a visit to the veterinarian is certainly in order.

Many cats vomit on occasion, but cats that vomit more frequently than once per week or that show signs of lethargy, weakness, decreased appetite, blood in the vomitus, increased thirst, increased or decreased urination, or simultaneous diarrhea should be evaluated by a veterinarian promptly.

A common complaint—and in most cases a relatively benign cause of feline vomiting—is the disgorging of a hairball, a damp, cylindrical wad of undigested hair, moistened by bile and other digestive fluids. It is not uncommon for a cat to expel a hairball once every week or two without any enduring problems. Indeed, a serious complication might occur if a cat does not bring up a hairball occasionally, since a clump of matter that has passed from its stomach into its intestinal tract could cause a life-threatening blockage.

Other frequently diagnosed causes of feline vomiting include the ingestion of such substances as the leaves of poisonous plants, spoiled cat food, various human medications, pieces of string or yarn, antifreeze, certain human foods (chocolate or onions, for example), or any number of objects that a cat might find lying about on the floor—paper clips, rubber bands, and the like.

A vast array of other causes of feline vomiting include: internal parasites, a wide variety of gastrointestinal conditions such as constipation and inflammatory bowel disease, obstruction due to an ingested foreign object, the presence of benign or cancerous gastrointestinal growths, and a wide range of metabolic diseases including diabetes, kidney disease, and hyperthyroidism. Diagnosing the cause of frequent vomiting in cats begins with a thorough history from the owner, a physical examination of the cat, and then bloodwork and fecal examination to rule out possible toxicities, parasites, and metabolic diseases. If everything seems normal, x-rays and ultrasound, which can be helpful in finding masses, foreign objects, and other gastrointestinal tract problems, may be recommended. If these are not fruitful, a biopsy of the intestinal tract to rule out cancer or inflammatory bowel disease may be pursued.

Regardless of the cause, cases of protracted feline vomiting will need supportive care, often involving intravenous or subcutaneous fluid therapy, and feeding a bland, easily digested diet once the vomiting has stopped. An anti-emetic drug may be prescribed to stop the vomiting in cases of dietary indiscretion or certain metabolic diseases. Specific treatment, of course, will depend upon the diagnosis. Parasites will be addressed with deworming medication. Toxicities will be treated with appropriate antidotes or supportive therapy.

Suspected infections will be treated with antibiotics, and metabolic diseases will be treated with specific therapies directed at the disease. Obstructions may be removable via endoscopy (a flexible camera that is passed down the esophagus with the cat under general anesthesia), but in many cases, these need to be removed surgically. Any cancers identified may be treated with surgery and/or chemotherapy. Inflammatory bowel disease, a common disorder in cats, is usually treated with dietary therapy, antibiotics and/or steroids.

Last updated 2021