When it comes to pain management in horses, the words "osteoarthritis" and "phenylbutazone" seem to work in tandem. But not all veterinarians are sold on the routine use of this drug in horses.

Phenylbutazone is a non-steroidal anti-inflammatory drug that has anti-inflammatory, analgesic, and anti-pyretic properties. Unfortunately, it also has known side-effects, including nephrotoxicity (toxic to the kidneys) and intestinal ulceration.

In contrast, newer NSAID firocoxib, designed specifically for horses, has fewer treatment-related adverse events than phenylbutazone and is effective at reducing lameness.

In a new study, "The use of force plate measurements to titrate the dosage of a new COX-2 inhibitor in lame horses," Willem Back, DVM, Cert. Pract. KNMvD (Equine Practice), PhD, Spec. KNMvD (Equine Surgery), Dipl. ECVS, from the Faculty of Veterinary medicine at Utrecht University in The Netherlands, and associate veterinary researchers, described the use of a force plate to determine the optimal dose of firocoxib in horses with osteoarthritis.

A force plate is a specialized piece of gait analysis equipment capable of objectively detecting subtle changes in loading and unloading of the limb to evaluate lameness.

Back and colleagues used the force plate in 64 horses with chronic lameness due to osteoarthritis, including navicular disease. Horses were treated with various doses of firocoxib (ranging from 0 to 0.25 mg/kg administered orally) and changes in lameness before and after treatment were analyzed.

According to the authors, 0.1 mg/kg firocoxib administered orally once daily was cons