Interaction of Phenylbutazone and Bone Healing in Horses

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone and flunixin meglumine are used to reduce inflammation and pain from injuries, surgery, or bone fractures. New research has discovered that NSAIDs have the potential to inhibit bone healing in horses, 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.