Megacolon in cats is an extreme, irreversible dilation of the colon which requires swift treatment to prevent death. After treatment, megacolon will require long term management so the cat can live a normal life.
Causes of Megacolon
Chronic, reoccurring bouts of constipation is the usual cause of megacolon. However, megacolon can occur in a cat which has never had a problem with constipation. Feces become impacted and harden within the colon when the muscles of the colon wall become unable to move things along normally. The section of the colon where the impaction is distends and never returns to normal size even after the impaction is removed.
Symptoms of Megacolon
The symptoms of megacolon in cats is the same as constipation. The cat will not be having normal bowel movements and will be straining in an attempt to defecate. A small amount of dry, hard feces may be passed with each attempt and/or loose, bloody stools mistaken for diarrhea may find it’s way around the impaction in the colon and be passed.
Cats will also present with other symptoms after a prolonged time of being unable to defecate – lethargy, loss of appetite, weight loss, vomiting and signs of discomfort when the abdominal area is touched. Megacolon usually afflicts middle-aged male cats, but can occur in a cat of any age or gender.
Exam and Treatment
When megacolon is suspected, a veterinarian will feel of the abdomen for a enlarged, full colon. An X-ray will follow to discover how severe the megacolon is and if there is an obvious cause, such as if the cat has swallowed a foreign object or had/has a fractured pelvis.
Treatment for megacolon begins with the vet administering an enema to try and dislodge and move out the colon impaction. More than one enema may be required and even then may not move the impaction. In that event surgery will become necessary to clean out the colon and in the most extreme cases of megacolon when the colon will not respond to treatment, most of the cat’s colon will be removed.
Once the colon has been cleansed of all impaction, long term management of the megacolon begins. Your veterinarian will recommend a life-long diet plan best suited for your cat, either a high fiber diet to keep things moving along through the permanently stretched-out colon or a low fiber, moisture filled diet.
Drugs may also be prescribed, such as laxatives, stool softeners or drugs to help the colon contract and propel the feces along their route.
Source: http://pets.webmd.com/cats/cat-constipation-and-fecal-impaction