Digestive Disorders

Cats regurgitate for a variety of reasons, some not at all serious: eating too quickly, swallowing hair when grooming, a tight cardiac sphincter, or a dilated esophagus.

In vomiting, stomach and abdominal wall contractions force back up the stomach contents, which have a distinctive acidic smell. This is usually more serious than regurgitation.

Vomiting and diarrhea are fairly common in cats, and may result from changes in diet, food intolerances or allergies, poisons, ingested foreign bodies, infections, or parasites.

Older cats may develop liver, kidney, or pancreas conditions, hyperthyroidism, inflammatory bowel disease or colitis, and intestinal cancers.
 
One common feline food intolerance is to milk. Kittens produce the enzyme lactase to digest milk sugar, lactose, but adult cats often lack this enzyme, and milk may cause diarrhea. Other intolerances are less easily isolated.

The cat's liver is very slow at processing some drugs; for example, it takes about 72 hours to break down aspirin, so even small amounts are dangerous if given more than twice weekly.

Other medications are lethal in even smaller amounts. The kidneys can be irreversibly damaged by some ingested poisons, most notably antifreeze.

Ingested objects, such as string, can loop around the tongue or anchor in the intestines. Never pull out such ingested objects, because you can cause damage; seek veterinary help.

Feline immunodeficiency virus (FIV), feline leukemia virus (FeLV), and the preventable feline panleukopenia virus (FTP) all cause vomiting and diarrhea.

The parasite giardia is difficult to confirm, and may be more common than is realized; vomiting is often the only sign of heartworm. Vomiting caused by inflammation to the stomach may be stress-induced in some cats.