Why Does My Cat Keep Vomiting

1 Why Does My Cat Keep Vomiting

In most cases, finding the exact cause of vomiting takes slow elimination. The cat below, ‘Pangpang,’ kept vomiting with no cure; after a series of checks, the real cause was found. Let’s see the visit.

Background

Basic info: Pangpang; 3 years; Exotic Shorthair; neutered male;

Vaccine/deworm: yearly FVRCP, no regular deworming.

Diet: kibble, occasional yogurt.

History: vomiting started half a year ago, several times a day at worst, once every 2 weeks at best, never stopping. The owner, distressed, had basic blood work (CBC, chemistry) and a panleukopenia test nearby—all normal—then referred to us for endoscopy.

Physical exam

No obvious abnormality.

Lab tests

As other tests were normal and lifestyle/diet unremarkable,

endoscopy was a good choice—directly viewing the upper GI, finding ulcers, masses, polyps, diverticula, and subtle mucosal changes (congestion, edema, color) that ultrasound and X-ray can’t.

For suspicious lesions, a small tissue sample can be taken for pathology. So we anesthetized Pangpang for gastroscopy and also collected feces to rule out gut parasites.

Yet Pangpang’s gastroscopy was normal—from mouth through esophagus, cardia, to stomach, all smooth, opening/closing well, normal motility. Finding nothing, the owner declined further sampling and went home.

Treatment

The local vet was stuck; with a limited budget, after consultation they tried a triple-drug regimen, a diagnostic treatment for Helicobacter-related disease.

After medication, vomiting stopped. But the owner said it relapsed if off meds over a week. Overall frequency dropped a lot over these months, and the owner was relieved—first effective treatment. But a cat can’t take medicine for life; there must be an underlying problem. Testing is easy—the problem is money.

Chronic vomiting has many differential diagnoses: gastric outlet obstruction (pyloric stenosis, foreign body, antral mucosal hypertrophy), megaesophagus, IBD, hypertension, hyperthyroidism, liver failure… How to help Pangpang within budget? After re-checking chemistry and ultrasound (normal), the local vet again referred the owner to us for a better plan.

Prior blood and physical exams ruled out some diagnoses, but many can’t be confirmed or excluded by a single blood draw; doing all would far exceed budget. So, combining clinical signs, blood work, and drug response, we chose a food-elimination trial to confirm/exclude food allergy.

What is a food-elimination trial? Is it costly? the owner first asked. It’s designed for suspected food allergy: feed only a hypoallergenic diet (not the so-called ‘hypoallergenic’ kibble from online shops—those just use rare meats; they work only if the cat is allergic to common meats like chicken/fish/beef, not grains or other items). A true hypoallergenic diet hydrolyzes ingredients into small-molecule proteins, greatly lowering allergy risk.

Persist 1–2 months and see if signs improve/disappear. If they do, switch back to the old food for a food challenge; if signs return, food allergy is confirmed.

Carefree Pangpang

So back to the owner’s question: food allergy costs no extra—just the price of food. But it’s slow, needs the owner’s cooperation, and is hard in multi-cat homes.

Luckily Pangpang is an only cat and the home doesn’t free-feed, so the trial was feasible.

One month passed: Pangpang off all drugs, vomited twice. Second month: no vomiting. After switching back to old food, vomiting returned within a week.

The result was clear.

Later notes

Pangpang finally left drugs and vomiting, but must avoid certain foods—no random treats, only one fixed kibble (after trials, at least 3 common foods made him vomit).

Luckily Pangpang cares nothing for food; happy just with the owner, he joins night runs and outings, bold and cheerful.

Vet’s note

Food allergy isn’t common, so it’s usually absent from acute vomiting/diarrhea differential lists; but with stubborn vomiting/diarrhea, after ruling out parasites, infection, and systemic disease, consider it even if unlikely (food allergy more often shows as chronic diarrhea/colitis).

Two ways to diagnose food allergy: the elimination trial above and a novel-protein trial—both change the diet to watch for improvement, just with different foods; pick by whether you can cook and have time.

If neither works, a blood allergen test can start from the strongest-reactive foods, greatly improving efficiency.

Chronic vomiting/diarrhea animals often keep normal spirit/appetite at first and look healthy apart from the vomiting/diarrhea, lulling owners into thinking it’s fine. They wait until the cat is very thin to see a vet, when complications raise diagnostic difficulty, multiply cost, and add mortality risk.

Pangpang was lucky—diagnosed before severe complications, no drugs needed, lifespan unaffected.