Megacolon

Megacolon means an abnormally large colon. In cats it is the end result of long-lasting constipation: the muscle of the colon wall stretches and weakens, and can no longer push stool out. Hard, dry stool packs the bowel, and the problem tends to get worse over time. Middle-aged male cats are most often affected, and in many cases no cause is found. Others have a narrowed pelvis after an old injury, nerve problems or a blockage.

Signs include repeated visits to the litter box, straining, crying, passing small amounts of hard stool or liquid, vomiting, a poor appetite and weight loss. A cat that strains in the litter box may have a urinary problem instead, and a male cat that cannot pass urine is an emergency. See urinary blockage. Because the signs overlap, a cat that strains needs a vet the same day.

A vet can feel the full colon, confirm it with an X-ray and test for causes such as dehydration or chronic kidney disease. Treatment can include fluids, an enema given under care of the vet, diet changes and medicines to help the bowel move. Never give a human laxative or enema to a cat. In severe, repeated cases surgery to remove part of the colon can help. Ask your vet about long-term management.