Pet Vet: Cat’s hard stool could signal problem with colon function

December 26, 2016

I have received several emails — four, actually — that have a common theme: cats and their common problem, which concerns their bowel movements. We’ll discuss a cat named Dolly, but all four have a similar scenario.

Dolly is 7 years old, female long-haired calico that, according to Sandy, spends most of her time indoors. About three years ago, Sandy noticed that Dolly was not having regular bowel movements. When she did produce stool, it was minimal in amount and very hard in texture. Every few weeks, Sandy would find a huge pile outside the litter box on the floor and sometimes out in the yard on the grass. On three occasions in as many years, Dolly has been to her veterinarian for this problem. Radiographs and enemas were performed each time. Dolly was especially uncomfortable before her last visit.

Sandy has been following the directions given by her veterinarian: feeding Dolly a high-fiber prescription dry food with a small amount of canned food containing an additional fiber supplement, and giving her a hairball preventive daily. Even with these efforts, Dolly is still having problems.

This presentation, as so well-described by Sandy, is something we do see in our feline patients on a somewhat regular basis. What Dolly is experiencing is a form of constipation that likely involves the colon or large intestine. This type of problem can be a primary colon issue or may involve another system in the body that secondarily results in a colon problem.

To understand what might be happening with Dolly, let’s first understand a little bit about the location and function of the colon. The colon is the end section of the digestive tract. It is connected to the small intestine at its beginning and to the rectum at its end. The main functions of the colon are to reabsorb water from the stool and move it out of the body. This desiccation helps form the stool so it is not simply a liquid mess and it also is a method for conserving water within the body. When the colon is disturbed for any number of potential reasons, its function is altered and the result is usually a loosening of the consistency of the stool.

This is not the case for Dolly. In fact, her problem is on the opposite end of the spectrum. It sounds as though Dolly’s fecal material is spending too much time in the colon and, as a result, becoming too dry and hard because of normal colon function. In other words, the colon is only doing its job in reabsorbing water but the stool is not being processed along in a timely fashion. This can be a problem with colon motility or may reflect a problem with overall body hydration.

One condition in feline patients is termed "mega colon." With this condition, the colon becomes dilated and does not function normally in moving the stool out of the body. This leads to increased time for the feces within the colon, which leads to excess desiccation and firmness. These patients have varying degrees of difficulty in defecating, some to the point at which they simply cannot have effective bowel movements. Sandy in her letter shared the fact that Dolly’s veterinarian assured her that Dolly does not have mega colon. This is good news.

Other possible reasons for delayed emptying of the colon revolve around decreased motility. These can be difficult problems to definitively diagnose; however, there are medications that can increase colonic motility. The most commonly used medication is called cisapride.

In Dolly’s case, I would encourage Sandy to have her veterinarian check a blood sample and do a urinalysis. As I mentioned earlier, decreased hydration or mild dehydration can lead to extra dry feces. This can occur with cats that are dealing with kidney disease. A change in stool consistency from normal to very firm can be an early symptom.

Hopefully, a satisfactory solution can be found for Dolly, as this can be a very uncomfortable condition to live with. I have had many cases in my experience that have responded well to cisapride as long as there are no other underlying issues.




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