The short answer is that there is currently no feed or feed additive or supplement that will help treat and/or maintain comfort for your horse’s arthritis. While there are many OTC (over-the-counter) products that are popularly touted and promoted for treating arthritis, such as asomega-3 fatty acids, glucosamine and chondroitin, copper, manganese and zinc, vitamin E and herbs, there is no clear science-based evidence that these products have any benefit. In fact, most of the evidence cited is anecdotal for both horses and humans.
There are two reports on glucosamine and chondroitin for humans that found approximately 70% of these commercial products did not contain the levels of the active ingredients listed on the packaging. So not only are there concerns with effectiveness, but there are also issues with the right amount or dosage. If the human industry has difficulty guaranteeing active ingredient levels, and the animal industry has less regulatory oversight, then draw your own conclusions.
That being said, there are injectables with hyaluronic acid that can provide some benefit for your horse’s arthritis symptoms. You need to visit your veterinarian to determine if this type of product would help. There are NASIDS (non-steroidal anti-inflammatory drugs) that have also been proven effective, but again, you need to discuss these options with a veterinarian.
I do believe that conditioning can delay the consequences of the disease. Overweight and out-of-shape horses will place more strain on their limbs; a body condition score of 5 (BCS 5) needs to be achieved. Exercise is critical, and it must be consistent and linear. An accomplished rider who has a true balanced seat will minimize the weight bearing effects on an exercising horse. The horse’s hooves are critical for balance and should be managed every six weeks. I discourage shoes for arthritic horses because shoes restrict the natural mechanism of the hoof with blood and fluid circulation in the lower extremities. We know the benefits of cross training and strengthening the core and supporting tissues with humans, but I have not given much thought about how that model could be applied to horses.
On a related note, I know two 60-year-olds who suffered from arthritis in both knees and their lower back. Both had knee replacement surgery. Afterward, they started cross training, weight lifting, maintaining healthy diets and watching their weight. As a result, neither one is experiencing regular pain and discomfort related to the arthritis or taking prescription medication. I am one of them. So conditioning in horses is just as important as it is for humans, but then that was a testimonial.