Constipation is a relatively common problem in older and overweight cats. The predisposition to a nerve-muscle breakdown in obese and geriatric cats that leads to a slowing or retention of fecal matter in the colon is the most popular theory for the mechanical cause of constipation. This can be a life-threatening problem at any age but especially in the older cat.
As the transit time of fecal matter decreases due to the inadequate strength of muscular contractions more and more water is absorbed from the colon resulting in dehydration of the stool. This loss of lubrication in turn makes it more difficult for the cat to evacuate the fecal material. In addition, as the stool collects the size of the colon increases and stretches the muscles causing fatigue. All of the toxic waste products that are normally eliminated on a regular basis begin building up in the bloodstream.
If this process happens slowly or intermittently you may not notice anything wrong with your cat until the process has advanced to a serious degree. In most cases the cat will initially strain to defecate in the litter box and later go off its feed, become depressed and even vomit as the condition progresses with time. A chronic and /or recurrent condition will result in weight loss. Clinically, the diagnosis of constipation is made by palpating the abdomen and discovering an enlarged colon.
The goal of treatment is to remove the obstruction without releasing an “avalanche” of toxic products to the rest of the body. Often the cat must be anesthetized so that the stool can be re-hydrated by a warm water enema in order to remove the fecal balls. Supportive care such as lactated Ringers solution, steroids, antibiotics and a heating blanket are often necessary as well.
Prevention focuses on trying to discover an underlying cause. Changing to a high fiber diet that will retain water in the colon for a longer period of time is a common approach to managing this problem. In some cases changing to a diet with a higher digestibility and thus lower the volume of stool may be more effective. Supplementing with oral medication such as Lactulose to help lubricate the colon and slow the absorption of toxic waste is often given. Nerve-muscle stimulants such as Propulcid are needed in the more severe cases. As a last resort some cats will only respond to surgery rather than to manipulating the diet and dispensing medication.
In most cases the problem gets worse with time and the constipation episodes become more frequent. Constant vigilance is needed in these cases along with consistent use of medication and strict adherence to the prescribed diet.