04/18/2026
๐๐๐ฌ๐๐๐ซ๐๐ก ๐๐ฉ๐๐๐ญ๐: ๐๐ซ๐ ๐จ๐ซ๐๐ฅ ๐ฃ๐จ๐ข๐ง๐ญ ๐ฌ๐ฎ๐ฉ๐ฉ๐ฅ๐๐ฆ๐๐ง๐ญ๐ฌ ๐๐๐ญ๐ฎ๐๐ฅ๐ฅ๐ฒ ๐๐๐๐๐๐ญ๐ข๐ฏ๐ ๐๐จ๐ซ ๐ก๐จ๐ซ๐ฌ๐๐ฌ? ๐ฆด๐ด
Equine osteoarthritis is one of the most common chronic conditions affecting horses (Baccarin et al., 2022). So naturally, weโre always looking for ways to manage it, especially in our equine athletes and aging horses who experience higher joint strain.
One of the most common questions I get during consults is about oral joint supplements. Theyโre appealing for good reason: non-invasive, easy to feed, and widely available. But theyโre also expensive and the science behind them has been mixed.
In fact, one study found 48% of horse owners felt there wasnโt enough research to support joint supplement efficacy, yet 90% were still willing to use them for prevention or treatment (Swirsley et al., 2017). That gap likely comes from the mindset โThey might not help, but they wonโt hurt.โ
And thatโs understandable when youโre dealing with a condition as common and impactful as osteoarthritis, doing something feels better than doing nothing.
But hereโs the good news ๐
Researchers at Michigan State University have been working to give us clearer answers, and a newly published study is helping move the conversation forward (Harbowy et al., 2026). Article linked in comments!
โก๏ธ Letโs break down what this new research actually tells usโฆ
๐ฌ ๐๐๐ญ๐๐ซ๐ข๐๐ฅ๐ฌ ๐๐ง๐ ๐๐๐ญ๐ก๐จ๐๐ฌ (๐๐ง๐ ๐ฐ๐ก๐ฒ ๐ข๐ญ ๐ฆ๐๐ญ๐ญ๐๐ซ๐ฌ!)
Researchers at Michigan State University evaluated 40 horses with chronic lameness (AAEP 2โ4) associated with osteoarthritis.
Horses were carefully balanced by age, body condition, weight, and anticipated workload, then assigned to:
โข A joint supplement group (Cosequin ASU)
โข A control group (placebo; all-purpose flour)
To strengthen the study, each of these groups were further divided into two sub-groups and assigned different colors and scented additives to keep the treatments blinded and also create the perception there were four treatments to rule out any bias.
This is a strong experimental design addressing common issues seen in supplement research such as small sample sizes, lack of controls, and bias. This is important because the quality of the design determines how well we can interpret and ultimately trust the results.
๐๐๐ฌ๐ฎ๐ฅ๐ญ๐ฌ
Horses were evaluated every other week over 6 weeks and numerous variables were considered at each timepoint:
Lameness Grade: Treatment did not impact lameness grade (P>0.05) but all horses showed improvements between day 0 and 28 (P=0.045).
Forelimb Vector Sum: Horses on the oral joint supplement had greater forelimb asymmetry than those in the control group (P=0.042).
Pelvic Height: Treatment did not impact minimum or maximum pelvic height.
Stride Length: The stride length at the walk and trot did not differ between treatments.
๐๐ข๐ฌ๐๐ฎ๐ฌ๐ฌ๐ข๐จ๐ง
๐พ๐๐๐ ๐
๐๐๐ ๐๐๐๐ ๐๐๐๐?
Overall, the oral joint supplement did not contribute to any positive changes in horses with osteoarthritis. These findings are not surprising and do align with previous research. While in vitro (cell culture) studies showed promise, studies completed in vivo (in the horse) had unclear clinical implications.
๐พ๐๐ ๐
๐๐๐ ๐๐๐๐ ๐๐๐๐๐๐?
Joint supplements are a huge supplement category and historically have contributed to 34% of supplement sales (Oke et al., 2010). This is likely because equine osteoarthritis is the leading cause of lameness in horses (McIlwraith et al. 2012). This degenerative joint disease has been shown to affect an estimated 50% of horses over the age of 15 and up to 90% of horses 30 years and older (van Weeren et al., 2016).
๐๐ฒ ๐๐๐ค๐๐๐ฐ๐๐ฒ๐ฌ
Overall, the evidence suggests that joint supplements may not be a worthwhile investment. Instead, focus on:
๐ฅ Balancing the diet to ensure nutrient requirements are met and the horse maintains a healthy weight.
๐ก Ensuring housing emphasizes adequate turnout time instead of prolonged stall confinement
๐ Building exercise programs that include warm-up and cool down-periods and focus on consistent low impact movement, strengthening exercises, cross training, and proper conditioning
๐๐จ๐ญ๐ญ๐จ๐ฆ ๐๐ข๐ง๐: While feeding a joint supplement may be easy, a well-rounded and holistic management approach is more likely to support your horseโs joint health in the long run.
* Iโll add that, yes, this study evaluated a single supplement. However, many joint supplements on the market contain similar ingredients, often at even lower inclusion rates. While Iโll continue digging into the literature, there currently isnโt strong, consistent evidence identifying a specific ingredient or combination that reliably improves osteoarthritis outcomes in horses. And realistically, if a clearly effective option existed, it would be widely recognized and supported by the research at this point.
But now I am curious - Do you currently feed a joint supplement and will this impact your decision to use one in the future?
Cheers,
Dr. DeBoer
Baccarin, RYA, Seidel SRT, Michelacci YM, Tokawa PKA, Oliveira TM. Osteoarthritis: A common disease that should be avoided in the athletic horseโs life. Anim. Front. 2022;12:25โ36.
Swirsley N, Spooner HS, Hoffman RM. Supplement use and perceptions: a study of US horse owners. Journal of equine veterinary science. 2017 Dec 1;59:34-39.
Harbowy RM, Robison CI, Tillman I, Manfredi JM, Nielsen BD. Efficacy of an oral chondroprotective joint supplement on stride length and gait symmetry in aged geldings with chronic lameness. Animals. 2026;6(8):1230.
Oke S, McIlwraith CW. Review of the economic impact of osteoarthritis and oral joint supplement use in horses. AAEP Proc. 2010;56:12-16.
McIlwraith CW, Frisbie DD, Kawcak CE. The horse as a model of naturally occurring osteoarthritis. Bone Joint Res. 2012;1(11):297โ309.
van Weeren PR, Back W. Musculoskeletal disease in aged horses and its management. Vet. Clin. N. Am. Equine Pract. 2016;32:229-247.
