Idiopathic Megacolon

by: Dr. Matthew Mottel from Animal Care Center

L.S. (Pronounced "Ellis") is a 5 year old, neutered male, silver colored cat who presented one morning to us with a 3 day history of constipation. Similar clinical signs were seen about 6 months ago. The owner reported that during the last 24 to 36 he had become reluctant to eat or drink, was slightly lethargic, and may have vomited a small amount of a white foamy liquid once or twice but the owner was unsure. On initial physical examination L.S. was bright, alert, and his vitals were within normal parameters. Auscultation of his chest revealed no cardiac murmur or arrhythmias and his lung fields were clear of any adventitious sounds. Palpation of his abdomen revealed a large, firm, distended colon. Mild discomfort was noted while palpating his abdomen. The remainder of his examination was unremarkable. After discussion with the owner, we proceeded to take abdominal radiographs.

Abdominal radiographs, shown below, revealed a large amount of fecal matter within the dilated colon. The diameter of the colon measures greater than 1.5 times the length of the 7th lumbar vertebra. There were no other abnormalities appreciated. This information allowed us to diagnose L.S. with a condition called idiopathic megacolon. Blood work performed on him revealed only a mild dehydration.

Megacolon is a condition in which the patient suffers from colonic hypomotility and persistent dilation of the colon. The most common clinical signs are constipation or obstipation. The cells lining the colon become damaged and there is disruption of normal blood flow supplying the colon. In severe, refractory cases unresponsive to medical treatment surgical options may need to be considered.

L.S. was admitted to the hospital for further care. Subcutaneous fluids were given to rehydrate him. After 3 enemas he had not produced any feces. At this time he was given a sedative to allow for manual evacuation of the impacted fecal material. After this was completed he was given another bolus of subcutaneous fluids. The owners took L.S. home later that evening with medications to help prevent recurrence of his constipation. Lactulose is an oral hyperosmotic liquid laxatives that works by stimulating colonic fluid secretion and propulsive motility. A second medication, Cisapride, is a small pill best given 30 minutes prior to a meal that will promote gastric emptying and increase small intestinal and colonic motility. He was also sent home with a prescription diet that is specially formulated to help patients who suffer from constipation. We recommended that L.S. be encouraged to drink water and suggested trying a circulating water fountain for him. Limiting stress and ensuring proper litter box hygiene are also key components to managing his condition.

At recheck, L.S. was back to his happy self according to the owner. He had been receiving his medications, enjoying his new food, and was loving his new water fountain.