Common Causes of Cats Vomiting: What's Happening?

Understanding the exact cause of a cat's vomiting often requires a meticulous process of elimination. Take "Pang Pang," a fluffy feline who had been suffering from persistent vomiting. After a series of thorough investigations, we finally uncovered the true culprit behind his ongoing discomfort. Let's delve into his diagnostic and treatment journey.

Background Information

Basic Details: Pang Pang, a 3yearold, neutered male, is an exotic shorthaired cat.

Vaccination and Deworming History: He receives an annual vaccination for feline distemper and is not dewormed regularly.

Diet: Pang Pang eats dry cat food and occasionally gets a treat of yogurt.

Medical History: Half a year ago, he began vomiting, with episodes ranging from several times a day to once every two weeks. Despite the frequency varying, the vomiting never ceased. Concerned for his wellbeing, his owner took him to a nearby veterinary clinic for basic blood tests (complete blood count and blood chemistry) and tested for feline distemper, but no abnormalities were found. Consequently, he was referred to our hospital for an endoscopic examination.

Clinical Examination

No significant abnormalities were observed.

Laboratory Tests

Since all other tests were normal, and there were no peculiarities in his lifestyle or diet, an endoscopy was deemed an excellent diagnostic tool. This procedure allows for direct visualization of the upper gastrointestinal tract, revealing serious conditions like ulcers, tumors, polyps, and diverticula. It also detects subtle changes in the mucosa, such as congestion, edema, and color changes, which are not visible on ultrasound or Xrays. Additionally, suspicious areas can be sampled for pathological examination. Thus, we agreed to anesthetic endoscopy for Pang Pang, and we also collected a fecal sample to rule out intestinal parasites.

However, the endoscopy of Pang Pang's stomach also revealed no abnormalities. The procedure was uneventful, with the mucosa appearing smooth, the openings functioning properly, and normal peristalsis. With no abnormalities found, the owner declined further sampling and returned home.

Treatment

At this point, the local veterinarian was at a loss. Considering the owner's budget constraints, a consultation was held to consider a triple therapy for Helicobacterrelated diseases as a diagnostic treatment.

After the medication, Pang Pang's vomiting was finally controlled. However, the owner reported that the vomiting recurred after stopping the medication for more than a week. Although the frequency of vomiting had decreased significantly over the past few months, the owner was relieved to see improvement. However, the thought of lifelong medication was unsettling. The underlying issue was not yet identified, and the problem was the lack of funds.

Chronic vomiting has many differential diagnoses, including gastric obstruction (pyloric stenosis, foreign bodies, hypertrophy of gastric antrum mucosa), megaesophagus, inflammatory bowel disease, hypertension, hyperthyroidism, liver failure, and more. How could we maximize our efforts to help Pang Pang with limited resources? After normalizing biochemical and ultrasound tests, the local veterinarian still recommended that the owner bring Pang Pang back to us for further investigation.

While previous blood tests and physical examinations could rule out some differential diagnoses, many conditions could not be confirmed or ruled out with a single blood test. If all tests were performed, the cost would far exceed the budget. Therefore, based on the animal's clinical presentation, blood tests, and response to medication, we decided to conduct a food elimination trial to determine or rule out food allergies.

What is a food elimination trial, and is it expensive? This was the first question the owner asked. A food elimination trial is a diagnostic method designed for animals suspected of having food allergies. It involves feeding the animal a hypoallergenic diet, not just the socalled hypoallergenic cat and dog foods available on the market, which only use rare meats. If the animal is allergic to meats like chicken, fish, or beef commonly found in commercial pet food, these diets may be effective. However, if the animal is allergic to grains or other substances, these diets will not be effective. True hypoallergenic diets involve hydrolyzing the food's raw materials into small molecular proteins, significantly reducing the animal's risk of allergies.

After 12 months of feeding the hypoallergenic diet, observe whether the animal's symptoms improve or disappear. If there is indeed improvement, the next step is to reintroduce the original food for a food challenge test to see if the symptoms reappear. If the animal experiences symptoms again, food allergies can be confirmed.

Happy and Carefree Pang Pang

So, to answer the owner's question, food allergies do not incur additional costs; it's just a matter of switching to a different type of cat food. However, the downside is that it takes a long time and requires the owner's cooperation, especially in multicat households.

Fortunately, as an only child, Pang Pang had no issues with food elimination testing, and his owner's home did not have the habit of feeding treats to pets. Therefore, they could cooperate with the food elimination trial.

One month passed, and Pang Pang had stopped all medications, vomiting twice in the meantime. In the second month, he did not vomit at all. However, after switching back to the old food, he vomited again within a week.

The results were clear.

PostTreatment Considerations

At this point, Pang Pang had finally摆脱了药物和呕吐的困扰，但需要忌口，不能随便吃零食，只能吃固定的猫粮~ (After trying at least three common cat foods, Pang Pang would vomit after eating them.)

Fortunately, Pang Pang was indifferent to food and was very happy as long as his owner was with him. He could even accompany his owner on night runs and outings, showing no sign of shyness and instead being full of enthusiasm!

Doctor's Reminders

Food allergies are not a common disease and are generally not included in the differential diagnosis list for acute vomiting and diarrhea. However, if you encounter persistent vomiting and diarrhea after ruling out common causes such as parasites, infections, and systemic diseases, food allergies should be considered, even if it seems unlikely (food allergies are more common symptoms include chronic diarrhea and colitis).

There are two methods for diagnosing food allergies: the food elimination trial mentioned above and the novel protein trial. Both involve changing the animal's diet to observe whether symptoms improve. The specific food used can vary, and owners can choose based on their cooking skills and availability.

If neither method is feasible, blood tests can be used to detect allergens, starting with the food that elicits the strongest reaction. This can significantly increase the efficiency of the investigation.

When dealing with chronic vomiting and diarrhea, animals often appear normal in terms of spirit and appetite, aside from the vomiting and diarrhea. This can lead owners to become complacent and believe that there is no cause for concern. However, if the condition worsens, the animal becomes very thin, and complications can increase the difficulty of diagnosis and treatment, as well as the cost, and even the mortality rate.

Thankfully, Pang Pang was lucky to be diagnosed before developing severe complications and without the need for medication, which did not affect his lifespan.