Contrary to common thought, large colon impactions more often result in mild colic—sometimes so mild that the owners don’t even notice. | Photo: iStock

The results of a study by British researchers suggest that colic caused by impaction in the intestine’s large colon does not usually cause severe signs of pain. Contrary to common thought, large colon impactions more often result in mild colic—sometimes so mild that the owners don’t even notice.

“Impactions can present with a whole range of signs and can have severe pain, but the more difficult ones for owners to recognize are those with more subtle changes in behavior, such as lying down more than normal, not eating all their food or finishing food slowly, or a reduction in the amount of droppings,” said Sarah Freeman, PhD, of the School of Veterinary Medicine and Science at the University of Nottingham, in the U.K. “All cases will suffer less and have a better chance of recovery if they are treated as early as possible, so having owners pick up subtle early signs is really important.”

Because the currently published research on impaction colic comes from referral hospitals—where cases are typically severe—Freeman and fellow researchers Kyra Jennings, BSc, and John Harold Burford, PhD, chose to look at initial farm calls for colic. They reviewed surveys from 69 U.K. equine veterinarians to gather feedback about first-time impaction colic visits over a one-year period. The researchers included 120 case reports in their study, selected based on the kind of colic and the location (impaction in the large left ventral colon or pelvic flexure). They reviewed breeds, gender, feeding styles, housing, time of year, exercise history, health history, clinical signs, diagnostic tests, treatment, and outcome in these cases to look for