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Category: Feline
Feline megacolon is a bowel disorder in which the colon is chronically enlarged or dilated. There are many possible causes, which may be congenital, acquired, or idiopathic (cause not known). Congenital megacolon is believed to result from a congenital lack of certain colonic nerve cells, leading to motility problems and bowel obstruction. Congenital megacolon occurs relatively infrequently in cats.
Acquired megacolon may result from numerous possible pathologic processes, which may occur inside or outside the colon and may or may not involve metabolic or neurological disorders. A considerable number of cases occur without an identifiable cause. Constipation and injuries to the pelvis are frequently encountered known causes of megacolon in cats. Ingested foreign bodies are a partially preventable cause of this condition as well.
Diagnosis of megacolon is based on the affected cat's history, and on physical examination and x-ray findings. Cats with megacolon typically will be chronically constipated, or obstipated, with no passage of feces. If not treated promptly, complications may occur, including intestinal obstruction, fecal incontinence, and overgrowth of bowel bacteria, which results from bowel immotility. Cats experiencing these complications may vomit and may be lethargic and anorexic (have no appetite). Cats with these symptoms may die if not treated.
Feline megacolon is a syndrome rather than a specific disease. Consequently, identifying the underlying cause of the megacolon, if feasible, and treating that cause, if possible, is important. Treatment of megacolon per se may include conservative medical therapy or surgery. Sometimes medical treatment alone is sufficient; however, in many cases medical treatment fails and surgery will be required to save the cat's life. In some cases surgery is the treatment of choice.
Medical treatment of megacolon involves removing the impacted feces by giving multiple warm water enemas over two to four days. Many cats have to be sedated or put under general anesthesia to allow the veterinarian to manually and gently remove the feces from the rectum. If anorexia or lethargy is present, antibiotics and fluid supportive therapy may be given.
Once the rectum is evacuated, future fecal impaction may possibly be prevented by adding fiber to a moist diet, such as psyllium-based supplements or canned pumpkin pie filling. Administration of laxatives and/or prokinetic drugs that help improve the motility of the colon may be helpful. Providing clean litter may help to encourage defecation, and help maintain bowel motility.
Surgery involves removing most of the colon (lower bowel). This procedure is called subtotal colectomy. Most otherwise healthy cats tolerate the surgery well. Surgery often cures the problem, and typically the constipation resolves. Post-operatively most do not experience any significant problems. Some cats may have soft stools after surgery or increased frequency of defecation, but they are rarely fecally incontinent.
If owners are unable to properly manage a cat with megacolon, and surgery is not an option due to concerns such as expense, then euthanasia is a humane alternative. |