Non-steroidal anti-inflammatory drugs (NSAIDs) are the cornerstone of treatment for many painful conditions in horses, including arthritis, laminitis, and colic.
Although these drugs are an important component of therapy for these diseases, overuse and misuse of NSAIDs can result in gastrointestinal injury, kidney damage and even death in horses.
NSAIDs may help mask lameness while reducing pain, swelling, and inflammation, but they can also be very harmful to the equine, whether pet or athlete.
NSAIDs can contribute to GI ulcers, diarrhea from colitis and colic, which all may trigger bouts of laminitis. Even short term NSAID use has the potential for renal (kidney) and liver toxicity, and may decrease a horse’s health and performance.
Research has shown that NSAIDs may also slow down the healing process of soft tissues. This means that the horse on NSAIDs may look normal and not have pain evident, but the tissue is weaker longer and at a higher risk for re-injury during the extended healing period.
The USEF now requires an “NSAID Disclosure form” to be filed with the Steward/Technical Delegate if more than one NSAID is used during a competition or in the five days preceding a USEF competition. The use of Bute and Banamine together is currently prohibited.
Researchers at North Carolina State University’s College of Veterinary Medicine have investigated NSAID's in horses with colic-related intestinal injury. This research has uncovered previously unknown adverse effects: NSAIDs actually retard healing of damaged gastrointestinal tissue.
New research has discovered that when nonsteroidal anti-inflammatory drugs such as phenylbutazone and flunixin meglumine are used to reduce inflammation and pain from injuries, surgery, or bone fractures in horses, they have the potential to inhibit bone healing, especially in the early stages.
Higher doses and longer periods of use were linked to increased inhibition of bone healing in studies with rabbits and rodents. In the single study involving horses, biopsies were taken from the bones of horses receiving phenylbutazone and from a control group not receiving the medication.
At 16 and 30 days, there was less mineralized tissue in the biopsy sites in horses that had received phenylbutazone.
Though the difference in mineralization was minor, it could be important in how quickly and strongly bones repair themselves. Horse owners are advised to consult a veterinarian on the use of phenylbutazone or other NSAIDs to relieve discomfort for any injury.