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| Jan 1, 2014 By: Gary D. Norsworthy, DVM, DABVP (feline practice), Jen Olson, DVM VETERINARY MEDICINE |
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 (THINKSTOCK/EMRETOPDEMIR) |
Like each of you, we have been frustrated with the seemingly healthy cat that vomits twice a month or twice a week or twice a day. And like you and our clients, we have accepted these explanations for chronic vomiting:
1. He eats too fast.
2. She has a sensitive stomach.
3. They’re just hairballs, and they are normal.
4. That’s just the way he is, or, as one of our clients put it, “He’s just a puker.”
While buying one or more of these excuses, we kept asking ourselves if one of our human family members were vomiting this often, would we accept it or would we seek a diagnosis and proper treatment?
No more excuses
 Dr. Gary D.Norsworthy |
In pursuit of the etiology of this problem, we performed endoscopy for several years. Convinced that it had to be a primary gastric problem, we scoped the stomach and took multiple mucosal biopsy samples. The pathologists would report “mild lymphoplasmacytic gastritis” or “Helicobacter gastritis” or something else not very meaningful, and we would find something creative to do to try to solve the problem. We often used a corticosteroid, an H2 blocker, an antiemetic drug, a hairball lubricant, and an easily digested diet under the umbrella diagnosis of inflammatory bowel disease (IBD). Sometimes there was limited but often short-term response; sometimes there was no response. It did not take long until we felt bad for spending clients’ money with little to show for it.
 Dr. Jen Olson |
As ultrasound became an integral part of our practice, we decided to take a different approach. Instead of using endoscopy, we performed an ultrasound examination of the stomach. Consistently, the walls were uniform with measurements well within the normal range. Therefore, we moved down to the small bowel. With ultrasound we could look at a great deal of the small bowel instead of the inch or so of the duodenum that we sometimes could reach with an endoscope. It did not take long until a definite finding emerged—virtually every one of these cats had thickened small bowel walls. Suddenly it clicked. Chronic vomiting in cats is a small bowel disease, not a stomach disorder. It became clear that our gastric examinations and biopsies did not find the answer because we were looking in the wrong place.
Proof positive
These findings led us to the only logical next diagnostic step: full-thickness biopsies of several places in the small bowel. It was not long until the clouds parted, and we began to see things much clearer than ever before. After 100 cases, we put our findings together into a paper that was recently published in the Journal of the American Veterinary Medical Association (JAVMA).1
These 100 cats, and about 200 that followed, have shown us conclusively that chronic small bowel disease presents as chronic vomiting, chronic diarrhea, weight loss, or a combination of these. Only one of the 100 cats in the study had normal biopsy findings, making this diagnostic approach a “must do.” In addition to the one normal cat, we had diagnoses of chronic enteritis (usually IBD) in 49%, lymphoma in 46%, mast cell disease in 3%, and adenocarcinoma in 1%. Therefore, we tell clients that the most common disease is IBD, but lymphoma is clearly the second-most likely differential. In addition, the only way to differentiate between them is with surgical biopsies.
A new hope
Understanding chronic small bowel disease is the most significant thing that has happened in our practice since the introduction of feline leukemia virus vaccine in 1985.
Gary D. Norsworthy, DVM, DABVP (feline)
Jen Olson, DVM
Alamo Feline Health Center
San Antonio, Texas