Our Doctors spend an awful lot of time talking about joint supplements. Just yesterday I caught Dr. Lacher reading this article http://www.thehorse.com/articles/33601/oral-joint-supplement-efficacy-tested-in-senior-horses about joint supplements in older horses. So this week I thought we could chat a bit about these supplements. Personally I find most of them to be very tasty but more on that later.
Let’s start with why a joint supplement might or might not be needed in the first place. Lots of you ask your horses to perform as athletes. This is why I’m glad I’m a cat and don’t have such demands placed on my days. In the process of performing low level damage is done to the joints and particularly to the cartilage. This is part of exercise and is very normal. Most of this damage is readily repaired by the body but some of it is too extensive for the normal repair processes. When this happens we call it an injury and over time injuries can lead to arthritis.
So what’s a human to do? Well logic says if we give the body the stuff it needs to make more cartilage it will help those joints heal faster. Logic does say this but I have been doing a lot of research. After all with this much rain it’s not like this cat wants to go outside and play. Glucosamine and chondroitin sulfate have been shown to be absorbed by the equine intestinal tract and to have potential for anti-inflammatory effects. However, studies looking at the level of these molecules in blood and joints after oral and intravenous administration show they aren’t anywhere near high enough to be therapeutic. Hyaluronic acid fared even worse in studies. It was shown to be absorbed but nearly 95% of what was given was found in the feces. Studies have also been done in rats and dogs only, not horses. Fatty acids are new to the picture and the studies are preliminary at best. It looks like alpha-linoleic acid and cetyl myristoleate are the top candidates for horses. Moral of the story: There is some science behind the ingredients in joint supplements but most simply can’t be fed at high enough levels to be effective.
And then we get to the confusing part. Articles, like the one Dr. Lacher was reading, show that using objective measurements older horses with known arthritic conditions benefited from joint supplements. One way this may work is that inflammation in a joint will cause glucosamine and chondroitin to increase. This is likely due to an increase in cell transport mechanisms secondary to inflammation. Some scientists theorize that these molecules also work as anti-inflammatories in the liver and kidneys where they reach much higher levels due to the filtering nature of these organs. Fatty acids work in the entire body to reduce inflammation. This means that some horses sometimes have been shown to respond for reasons we don’t fully understand.
Real world advice time. You have a horse you would like to give a joint supplement to but you aren’t sure which one to use. Start with a well known name brand such as Cosequin or the SmartPak brands. glucosamine and chondroitin sulfate are probably the most important ingredients. For the horse in intense work or with known problems fatty acids added to the chondroitin and glucosamine may increase the benefit. However, when it comes down to your horse the best answer is to pick a supplement, try it for 30 days, stop it for 30 days and see how you feel. At the end of the day your horse’s response is really the only one that matters.
I have posted links to many of the articles I read for this blog. Most are very sciency and I had to ask Dr. Lacher and Dr. Bourke for help interpreting them. They said they would be more than happy to do the same for you guys any time. Until next time may your litter box be clean and your food bowl full!
The bioavailability and pharmacokinetics of glucosamine hydrochloride and chondroitin sulfate after oral and intravenous single dose administration in the horse
Effect of glucosamine on interleukin-1-conditioned articular cartilage
Synovial fluid levels and serum pharmacokinetics in a large animal model following treatment with oral glucosamine at clinically relevant doses
Absorption, Uptake and Tissue Affinity of High-Molecular-Weight Hyaluronan after Oral Administration in Rats and Dogs
Biochemical basis of the pharmacologic action of chondroitin sulfates on the osteoarticular system
Effects of glucosamine hydrochloride and chondroitin sulphate, alone and in combination, on normal and interleukin-1 conditioned equine articular cartilage explant metabolism
Double blind investigation of the effects of oral supplementation of combined glucosamine hydrochloride (GHCL) and chondroitin sulphate (CS) on stride characteristics of veteran horses
Systematic Review of Efficacy of Nutraceuticals to Alleviate Clinical Signs of Osteoarthritis