I have a 10yo quarter horse who’s never had any soundness issues. We do a lot of hacking out and he gets ridden 6 days a week, 2 are serious training days about one to two hours each. We are moving up to Novice eventing this season. Would you suggest any joint supplements? I have heard feed through joint supplements are a waste of money. I am considering Adequan injections. SS

Dear SS,

Congratulations on your success in eventing and on having such a happy, healthy partner! You sound like an intelligent, caring horsewoman, so I took the time to actually look up some research papers for you to read yourself and make an intelligent, informed decision about the benefits of oral joint supplements.

The following papers have all been presented at the American Association of Equine Practitioners Annual Convention, meaning they have been peer-reviewed by other veterinarians and scientists for quality of research:

Effects of an Oral Nutraceutical on Clinical Aspects of Joint Disease in a Blinded, Controlled Clinical Trial: 39 Horses (2007)
Keegan and others from the College of Veterinary Medicine at the University of Missouri concluded that oral administration of a product containing cetyl myristoleate, glucosamine HCl, MSM, hydrolyzed collagen and other ingredients had beneficial clinical effects on horses with naturally occurring osteoarthritis.

Review of Glucosamine-Containing Oral Joint Supplements: Are They Effective in the Horse? (2006)
In this paper, Weese reports on a number of studies in both humans and horses that conflict regarding the efficacy of glucosamine (some say they work, some say they don’t). He concludes that veterinarians and horse owners who would like to give glucosamine joint supplements should familiarize themselves with nutraceutical products with proven quality and give therapeutic doses (10g orally per day) by carefully reading the label guidelines and ingredients.

Effect of Glucosamine and Chondroitin Sulfate on Mediators of Osteoarthritis (2006)
A study by Neil and others showed that glucosamine significantly reduced a number of mediators of osteoarthritis but chondroitin sulfate did not (at the concentration tested). They mention other studies that showed glucosamine and chondroitin sulfate in combination seem to be more effective than either compound alone.

Double-Blind Study of the Effects of an Oral Supplement Intended to Support Joint Health in Horses with Tarsal Degenerative Joint Disease (2002)
Dr. Hilary Clayton’s group at the College of Veterinary Medicine at Michigan State University demonstrated that horses with hock arthritis showed a significant reduction in gait asymmetry after receiving an oral joint supplement for just two weeks as compared with placebo.

Evidence of the Oral Absorption of Chondroitin Sulfate as Determined by Total Disaccharide Content After Oral and Intravenous Administration to Horses (2001)
Eddington and her co-authors provided the first proof of the bioavailability of chondroitin sulfate in this paper. Their work suggests that the molecule is absorbed after oral administration.

The conclusion I draw from these and other research papers is that there is some evidence that some ingredients in some joint supplements are effective. I recommend working with your veterinarian to develop an overall wellness plan to maintain your horse’s health and soundness as long as possible. This may include FDA-approved pharmaceuticals like the Adequan that you mentioned, and it may also include over-the-counter nutraceuticals as you see fit.