Intestinal Healing Delayed With Banamine and Etodolac

Horses with colic are often treated with Banamine, a non-steroidal anti-inflammatory drug (NSAID) that effectively reduces pain and inflammation. Although Banamine (flunixin meglumine) helps colicky horses feel and look better, the drug can have unwelcome side effects. Like other NSAIDs, Banamine can cause gastrointestinal ulcers and impair the healing process in the equine gut.

Researchers at North Carolina State University College of Veterinary Medicine recently designed a study to determine if a newer drug, etodolac, represents a safer alternative to Banamine for treatment of pain associated with intestinal injury.
Etodolac belongs to the drug class known as COX-2 (cyclo-oxygenase) inhibitors. These medicines effectively reduce pain and inflammation, and they are typically associated with fewer gastrointestinal problems than the older NSAIDs. Marketed as Etogesic, etodolac is a canine pain reliever that is being used increasingly in the treatment of equine pain.

For the study, 24 horses were anesthetized. During surgery, a portion of each horse's lower intestine was clamped for two hours, effectively stopping the blood flow to that section of gut. "We created an injury equivalent to an intestinal twist that occurs with colic," said Anthony Blikslager, DVM, PhD, associate professor of equine surgery at North Carolina State University.

After the intestinal blood supply was restored, horses were assigned to one of four groups. Groups one, two, and three received one of three treatments: Banamine, etodolac, or saline solution. The fourth group was not treated. Two intestinal biopsies were then taken from each horse; one from the area of injured intestine, and one from a portion of healthy intestine.

Upon recovery from anesthesia, horses were assigned pain scores. Horses receiving Banamine and etodolac had similar scores, indicating that the two drugs are roughly equivalent in their effectiveness as pain relievers.

In the laboratory, tissue samples obtained during surgery were analyzed to determine the health and integrity of the intestinal wall. Tissues taken from horses treated with Banamine and etodolac showed greater damage than tissues taken from horses treated with saline solution. The results of this study, which were published in the June issue of the American Journal of Veterinary Research, suggest that both drugs significantly hinder the recovery of intestinal tissue after injury caused by interruption of blood flow.

According to Blikslager, "We had hoped that etodolac would prove to be safer than Banamine for the treatment of colic in horses, but this doesn't seem to be the case. Overall, the benefits of using drugs like Banamine still outweigh the risks, but they must be used carefully. It's a good idea to use low doses and get horses off the drugs as soon as possible."

Blikslager's team is conducting additional research to identify pain-relieving anti-inflammatory drugs that can be given safely to horses at higher doses and for longer periods of time.

The etodolac study was funded by Morris Animal Foundation.

About the Author

Rallie McAllister, MD

Rallie McAllister, MD, grew up on a horse farm in Tennessee, and has raised and trained horses all of her life. She now lives in Lexington, Ky., on a horse farm with her husband and three sons. In addition to her practice of emergency and corporate medicine, she is a syndicated columnist (Your Health by Dr. Rallie McAllister), and the author of four health-realted books, including Riding For Life, published by Eclipse Press and available at or by calling 800/582-5604.

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