Equine osteoarthritis is expensive to manage, with estimated annual costs as high as $10,000-15,000 per horse to diagnose, treat, and medicate, explained Wayne McIlwraith, BVSc, PhD, DSc, FRCVS, Dipl. ACVS, director of the Orthopedic Research Center at Colorado State University, who discussed the economic impact of osteoarthritis and oral joint-health supplements (OJHS) at the 2010 American Association of Equine Practitioners Convention, held Dec. 4-8 in Baltimore, Md. In his review of a paper that he co-authored with Stacey Oke, DVM, MSc, McIlwraith explained that the value of a horse affected by osteoarthritis also decreases substantially.

The veterinary nutritional supplement industry collectively earns $2 billion per year, with more than half of that coming from the equine sector—34 % of equine products are OJHS. McIlwraith remarked that 89% of these nutraceuticals are purchased from sources other than veterinarians.

Of note, McIlwraith pointed out that in many cases these horses are rarely receiving a specific diagnosis if the joint-health product is not received directly through the veterinarian. Often, a horse presented to a veterinarian for lameness evaluation has received OJHS for months, with or without an accurate diagnosis. These OJHS are often used to manage osteoarthritis and navicular syndrome, and to control post-traumatic and post-surgical inflammation. And, despite a lack of objective data, many products are given prophylactically (preventively) to at-risk athletic horses, he said.

Recent studies in humans continue to yield contradictory results. Oral glucosamine and chondroitin sulfate supplements have not demonstrated a proven benefit for managing osteoarthritis despite years of favorable anecdotal reports. In light of this, McIlwraith stressed the need for validating products with in vivo (in the live horse) data and that drug manufacturers should be encouraged to do this. At this time there appears to be little incentive for drug companies to perform such studies, he explained