Oral joint supplements/nutraceuticals have been with us for a quarter of a century. It didn’t take long after their appearance for the question to be raised regarding the potential to actually prevent arthritis.
Few active horses escape the bane of arthritis.
There are now hundreds of studies looking at the ability of oral supplements to prevent the development of arthritis or slow its progression. For example, positive results have been found for Boswellia in mice (Wang et al 2014), mussel extract in rats (Chakraborty et al 2010), quercetin in rats (Gardi et al 2015), glucosamine in rats (Aghazadek et al 2014), glucosamine in overweight women (Runhaar et al 2016) and long term chondroitin sulfate in humans (Kahan et al 2009) just to list a few.
The situation in horses is a bit more complicated. Being natural athletes they often make whatever they are doing look easy but the sheer size of the horse means tremendous forces are generated on his joints. These are further magnified by obesity, work on uneven ground, pre-existing OCD or traumatic damage, any hoof imbalances, conformation imperfections, rider weight, rider errors and quite possibly genetics. Preventing arthritis will never be as simple as giving a supplement. Nevertheless, there is reason to think we can have a significant effect.
In one of the earliest equine studies, White et al 1994, it was found that a commercially available chondroitin and glucosamine supplement did not protect against arthritis induced chemically by injection into a joint. However, Vidella and Guerreo 1998 did find significant protection by both oral and injected chondroitin sulfate in a similarly induced condition. The only difference between injected and oral was the injected chondroitin worked faster.
A small unpublished study by Dr. Smith at Rood & Riddle in Kentucky looking at Thoroughbreds in training with and without supplementation with hyaluronic acid oral gel for 59 days found statistically significant decrease in the number of horses evaluated for lameness when supplemented. HA greatly reduced postoperative joint swelling following surgery for OCD lesions in the hock, Bergin et al 2006. Prevention of postoperative joint degeneration was also confirmed by a study looking at supplementation with ASU (avocado soy unsaponifiables) in a situation where damage was created surgically, Kawcak et al 2007. They found no effect on pain but greatly improved cartilage quality.
In the most recent study, Leatherwood et al 2016 treated young Thoroughbreds with 30 mg/kg/day of glucosamine sulfate for 84 days before injected a carpal (knee) joint with lipopolysaccharide, a bacterial product which induces inflammation. A matched control group was not supplemented. The glucosamine group showed reduced markers of inflammation and cartilage breakdown, increased marker of regeneration compared to the injected control group. That dosage produced a blood level of glucosamine very similar to what was reported to be preventative in laboratory animals.
What to use at what dosage is the million dollar question. Firm answers just don’t exist but the evidence points to keeping at the high end dosages for at least one of the three major joint ingredients – 10,000 to 15,000 mg glucosamine, 2500 to 3500 mg chondroitin, 100 to 200 mg hyaluronic acid.
That’s what I’ve been doing with our racing Standardbreds for the last quarter century, starting when they are broken. The difference in the incidence and severity of joint problems compared to the days before these supplements were available is undeniable. I’ve been around long enough to see both first hand!
Eleanor Kellon, VMD