Cats vomiting up partially digested or completely undigested food is one of the most common feline appointments that I see, several times a week at least. Other than the tendency to vomit up food, the cats I am writing of in this article are generally otherwise normal: good appetite, no weightloss, normal drinking patterns, normal attitude, etc.
I am glad when cat owners brings in cats with this presentation, as many feline owners just assume that some cats are just “pukers” and it is normal. It is true that some level of vomiting is not considered pathological in cats, but many would be surprised that is only 2 times or less per month. Any more than that, something is wrong and the “wrong” could potentially be something serious.
If physical examination with the chronically vomiting cat is unremarkable, my first diagnostic step is to run a minimum database of general blood work and urinalysis to rule out diseases that can adversely affect the upper gastrointestinal system in cats – there are many. I also run a stool analysis to rule out parasites and may take abdominal x-rays to rule out possible foreign body obstructions or masses that may escape detection on abdominal palpation on physical exam. Yes, I even run stool checks on strictly indoor cats…people would be amazed how often I find chronic GI parasites in indoor cats.
If all that is normal, then I generally will recommend an 8 week food trial with a hypoallergenic diet. My hypoallergenic diet of choice is Royal Canin Ultamino, a food that breaks down proteins to their individual molecular units call amino acids. This gives the kitty the protein he/she needs to meet his/her physiological needs, but breaking down the proteins in this fashion enables absorption in the gut without adverse reactivity. The goal here is to rule out or rule in food allergy.
If the diet works and the vomiting either ceases or reduces to two times per month or less, then we have proven food allergy. In this case, problem solved, just feed the hypoallergenic diet exclusively indefinitely. If the diet does not work after 8 weeks of exclusive feeding, then there is more work to do.
This is when the client is left with making a fairly major decision. After having ruled out metabolic diseases that commonly affect the gut (via blood work ans urinalysis), ruling out parasites with stool analysis, and ruled out food allergy via food trial, what is left is usually one of two possibilities: inflammatory bowel disease or lymphoma. Inflammatory bowel disease (IBD) is an autoimmune disease whereby the immune systems attacks its own tissues, in this case, the proximal gut. Lymphoma is a cancer of the gut. Both at first present virtually identically.
Early in my career, I recommended endoscopy for these patients, a procedure where under general anesthesia, a scope is passed down the esophagus into the stomach and small intestine to look around and take biopsies. This is then done from the other end, commonly called colonoscopy.
For many years now for these types of cases, I have long since lost faith in the diagnostic accuracy of endoscopy. I have seen cases where diagnoses were missed because the scope can only go so far from either end, missing 2/3 or more of the gut. I have also seen biopsies coming back false negative because the biopsies that endoscopy enables are sometimes too superficial for optimal diagnostic quality and disease pathology is missed.
My gold standard diagnostic recommendation for chronically vomiting cats is abdominal exploratory surgery where I take small but full thickness biopsies of the stomach and each segment of the feline small intestine. Each biopsy site usually only requires 1-2 sutures and have minimal impact on the gut.
Recovery is similar to the recovery of patient who undergoes a spay and we have a high probability of identifying the diagnosis to treat appropriately. Nonetheless, feline owners often have a hard time justifying exploratory surgery as a diagnostic tool. However, there are three reasons why exploratory surgery is the right course of diagnostic testing.
1.) IBD and lymphoma both present clinical identical at first and I cannot treat lymphoma based on a hunch (even if other factors made me lean more toward lymphoma as a diagnosis, one simply does not treat cancer without a confirmed diagnosis).
2.) If lymphoma is the diagnosis, treatment is easy and generally well tolerated. The protocol I currently use is the steroid prednisone in combination with an oral chemotherapeutic called chlorambucil. Both are dosed once daily orally for 4 consecutive days, then backed off to dosing once every 3 weeks for maintenance. Average remission rates approach 2 years which in feline time represents 10 plus years.
3.) If the diagnosis is IBD, then we have ruled out cancer (hooray!) and we can focus on treatment of IBD: usually daily to every other day dosing with the steroid prednisone alone. For some cats with milder disease, we can administer long acting steroid injections with depomedrol every 1-3 months.
Many clients are surprised at how complex the differential diagnoses and how involved the diagnostic process can be for the vomiting cat. It is often far more than they expect and it is up to the veterinarian to patiently and clearly explain the nuances and potential complexities of what may be causing the issue.
I saw many cases of this presentation this week which was my inspiration for writing about it. Since it is ever so common, it is my hope that this will help feline owners with chronically vomiting cats make the best decisions on behalf their cats as fully informed as possible.
Dr. Roger Welton is a practicing veterinarian and highly regarded media personality through a number of topics and platforms. In addition to being passionate about integrative veterinary medicine for which he is a nationally renowned expert, Dr. Welton was also an accomplished college lacrosse player and remains to this day very involved in the sport. He is president of Maybeck Animal Hospital , runs the successful veterinary/animal health blogs Web-DVM and Dr. Roger’s Holistic Veterinary Care, and fulfills his passion for lacrosse through his lacrosse and sport blog, The Creator’s Game.