Equine veterinarians commonly prescribe non-steroidal anti-inflammatory drugs (NSAIDs) for horses to treat a myriad of diseases, including colic, respiratory disease, and lameness. NSAIDs are also very common in human medicine, and they include such drugs as aspirin and ibuprofen. Most horse owners have probably used NSAIDs too, such as phenylbutazone, or "bute," in one of their horses at some point in time.

"NSAIDs are an invaluable medication and have a multitude of uses in equine medicine. When used appropriately, they are very safe for horses," said Bradley Nelson, DVM, a Washington State University equine medicine and surgery intern. "Like any medication, however, there can be side effects with NSAID use. It is important that horse owners only use these medications as directed by their veterinarian and when they are aware of the symptoms that horses with NSAID toxicity will demonstrate."

The positive effects of NSAIDs include pain relief (analgesia) and the reduction of inflammation and fever. When a horse is injured, the body responds by producing inflammation. The horse will then likely have some associated swelling, pain, heat, or redness in the affected area. This inflammatory process is a multiple-step pathway in the body and involves many enzymes. NSAIDs work by inhibiting an enzyme called cyclo-oxygenase (COX), which shuts down the pathway and reduces the inflammatory process. Depending upon the NSAID, other positive effects include blood thinning and the reduction of endotoxemia, or the presence of bacterial byproducts in the bloodstream.

The most commonly used NSAIDs are flunixin meglumine (Banamine) and phenylbutazone or "bute." Other NSAIDs equine veterinarians use include firocoxib (Equioxx), ketoprofen (Ketofen), etodolac (Etogesic), aspirin, naproxen, and diclofenac (Surpass). Flunixin meglumine is typically given to horses with pain originating from an internal organ, such as colic. Phenylbutazone is given for conditions that involve lameness or other problems involved with the horse's bones, ligaments, and tendons