Osteoarthritis medications were a hot topic at the 2007 American Association of Equine Practitioners convention, held Dec. 1-5 in Orlando, Fla., with four presentations on various medications during one half-day session alone.

In particular, David Frisbie, DVM, PhD, Dipl. ACVS, associate professor of veterinary clinical sciences at Colorado State University (CSU), discussed a study comparing clinical efficacy and joint health parameters of Surpass (topical liposomal diclofenac cream) to those of the commonly used oral non-steroidal anti-inflammatory medication phenylbutazone (Bute).

Does Surpass really work to improve joint health, or is it just another way of delivering a painkiller? CSU researchers set out to answer that question.

In 24 horses, carpal (knee) osteoarthritis was induced in one knee, and the horses were split into one control and two treatment groups. One treatment group got 7.2 g of Surpass on the affected joint every 12 hours for five days, while the other received 2 g of Bute orally once a day for five days. Horses were exercised on a high-speed treadmill daily, and lameness, tissue scores, biochemical scores, and biomarker scores were used to evaluate the efficacy of treatment.

Frisbie reported that the Bute- and Surpass-treated limbs got significantly better in terms of lameness scores. The cartilage glycosaminoglycan content in the Surpass-treated limbs was better than with Bute (meaning the cartilage was better hydrated and lubricated). There were also improvements in bone sclerosis (hardening) of the radial carpal bone and total erosion scores in the Surpass-treated joints.

"Both Surpass and Bute had sy