Q: My cat has been vomiting since approximately last September and I (and my vet) cannot find the problem. He vomits every day, lately several times a day. He has maintained his weight, throwing up mostly fully digested food. My vet has tried X-rays, blood testing, urinalysis, several prescriptions and many food changes. I am currently trying to determine if the vomiting may be a food allergy, and have started him on a limited ingredient diet made with turkey and potatoes. My vet said the next step would be to find a specialist to see why the cat vomits. That will be very expensive, so I am trying to see if I can eliminate a few possibilities first.
A: Every cat vomits occasionally and many times a harmless reason explains it, like hairballs, eating too fast or a sudden diet change. Vomiting every day, or several times a day like your cat is doing is certainly not normal.
In general, cats vomit from either a gastrointestinal disorder or a metabolic disorder. For example, cats can vomit from a gastrointestinal disorder such as food allergy or inflammatory bowel disease. They also can vomit from systemic disorders that have nothing to do with the gastrointestinal system, such as hyperthyroidism. Because vomiting has so many potential causes, diagnosing the reason for the vomiting can be challenging.
It sounds like your vet has run the routine, non-invasive tests required to come up with a diagnosis. When the first round of tests do not reveal a cause, a reasonable first approach is to change the diet to a bland, highly digestible prescription diet and see if that helps. I suspect from your letter that you’ve tried these diets. The next choice would be a hypoallergenic diet, meaning a diet that contains a protein source that your cat has never seen, such as rabbit, venison or duck. (Your vet likely carries prescription diets of this type). If dietary changes do not help end the cat vomit, further diagnostics may be necessary.
I suspect your cat might have inflammatory bowel disease. To determine this for certain, your vet will need biopsies of the intestinal tract. This can be achieved via endoscopy (my first choice) or exploratory surgery. Once a definitive diagnosis is achieved, appropriate therapy can be started. If you cannot afford endoscopy, your vet may be able to prescribe anti-vomiting drugs that can provide symptomatic relief, however, clinical signs are usually hard to control unless a true diagnosis is achieved.