A 10-year-old Thoroughbred broodmare awaits her morning meal. There is a 4-month-old foal by her side. She only eats about half of the ration, but shows no signs of distress. The barn manager is notified that his best mare is a bit off her feed and showing mild signs of depression. In the short time it takes him to get to the barn, the mare has begun circling her stall and pawing occasionally. In 30 minutes when the veterinarian arrives, the mare is sweating and her abdomen is distended. She is trying to lie down. With some coaxing she remains standing for a brief physical exam. Her heart and respiration rates are elevated and her oral mucous membranes are pale. No sounds of intestinal movement can be heard. Rectal examination reveals a very gas-distended large intestine. The tentative diagnosis is large colon torsion, also known as large colon volvulus.

The veterinarian quickly administers an analgesic for pain and passes a nasogastric tube to relieve fluid or gas distention of the stomach. She explains that the colon has likely twisted, obstructing the lumen (space within the colon) and cutting off the blood supply. For reasons not fully understood, broodmares four to 12 years old and three to six months post-foaling are particularly predisposed to this problem. The only hope to save the horse is a quick trip to a referral hospital and possibly emergency colic surgery.

The referral hospital is alerted and the colic team gets ready. The mare is loaded for the 45-minute trip. The foal is left at home.

Upon presentation at the referral hospital, the mare's abdomen is even more distended. Her mucous membranes have become bright red with increased capillary refill time. She is panting, sweating, and is in a lot of pain. She is taken across the weight scale and directly to the padded anesthesia drop area in case she lies down during the surgeon's examination. Analgesics are judiciously administered to keep the mare comfortable long enough to draw blood for pre-operative analysis, place an intravenous catheter, administer antibiotics and Banamine, and lavage her mouth to remove any feed material