Exploring Acetaminophen for Pain in Horses

Acetaminophen appears to be a safe medication to control pain in horses, according to researchers from the Virginia-Maryland College of Veterinary Medicine, though more study is needed before widespread use occurs.

“According to the researchers*, acetaminophen is the most commonly used medicine for pain and fever in human medicine. Acetaminophen does not have the detrimental gastrointestinal- or kidney-related side effects associated with certain nonsteroidal anti-inflammatory drugs such as phenylbutazone,” explained Laura Petroski-Rose, B.V.M.S, a Kentucky Equine Research staff veterinarian.

She continued, “Phenylbutazone, or bute, remains one of the most commonly prescribed drugs for pain and fever control despite the known side effects. Thus, having an alternative to nonsteroidal anti-inflammatory drugs for horses would be beneficial.”

As a first step in supporting the use of acetaminophen in horses, the researchers began by conducting a simple safety test. This involved administering 10 g of acetaminophen by mouth to horses either once or twice daily for 14 days. Routine blood examinations, gastroscopy, liver biopsies, and acetaminophen blood levels were analyzed.

Those results showed:

• Acetaminophen was absorbed after oral administration;
• No clinically important changes in blood parameters were appreciated;
• No change in gastroscopy scores were noted; and
• Multiple doses of acetaminophen did not accumulate in the body.

While this study showed that acetaminophen is safe for horses, more research is necessary before it should be used on horses. Also be aware that acetaminophen may be considered a prohibited substance under some governing bodies of equine sport.

Regardless of which pain medication your horse receives, be aware of the potential side effects associated with them by asking your veterinarian. Support the overall health of the gastrointestinal system—a frequent victim to medication side effects—by maintaining a consistent diet, offering plenty of water and forage, and supplying sufficient vitamins and minerals. Consider a gastrointestinal protectant from Kentucky Equine Research.

RiteTrac offers two lines of defense for the gastrointestinal tract, providing protectants and antacids for the stomach, and a time-released buffer for the hindgut. As a powdered supplement, RiteTrac can be mixed easily into a concentrate meal. Australian horse owners should look for these products.

“Triacton supports the intestinal tract in many ways. It features a highly digestible source of minerals and vitamins in an easy-to-feed pellet and includes yeast for hindgut support and improved fiber digestion,” Petroski-Rose shared. Triacton is especially appropriate for young horses, as it enhances bone density.

*Mercer, M.A., H.C. McKenzie, J.L. Davis, et al. 202o. Pharmacokinetics and safety of repeated oral dosing of acetaminophen in adult horses. Equine Veterinary Journal 52(1):120-125.