Equine Oral Joint Supplements
By Dana Gardiner
If you have looked in any feed or tack store, equine magazine or horse related website,
you have seen advertising for equine oral joint supplements. This topic is extremely confusing,
even for the experienced horse person. Although there is not a lot of data on equine oral joint
supplements, there is a lot of research currently underway to determine the total effects and
efficiency of their use. This has become a growing concern of the equine industry, especially
when dealing with performance horses.
Oral joint supplements (OJS) are considered a neutraceutical. This means that it is a
dietary supplement designed for medical use. It falls somewhere between a food and a drug,
mainly because it has an unestablished nutritive value. OJS are a relatively new approach to joint
health, mainly becoming popular in the last five years. They are to be utilized to heal or prevent
joint damage or lameness in athletic horses. They contain “building blocks” of normal healthy
Joints are any place that bones meet, allowing for movement and flexibility. The two
main areas of the joint that are most prone to problems are the cartilage and the synovial fluid.
Cartilage has no blood or nerves; therefore it cannot heal or repair itself. It is made up of
collagen, which gives it strength and elasticity. A loss of this collagen can cause cracking and
weakness which leads to lameness. Synovial fluid is a slippery fluid that fills the spaces between
joints. It is important for repairing cartilage, exchanging ions and keeping joint elastic and
lubricated. Synovial fluid needs antioxidants to help neutralize free radicals produced by heavy
exercise, as commonly seen in performance horses.
Important components that make up the joint are proteoglycans, which are molecules that
help make up collagen. Glycosaminoglycans (GAGs) are molecules that help attract and hold
water in the collagen. They help give collagen elastic qualities that make it a shock absorber and
stabilizer. Therefore, a loss in GAGs causes the joint to hold less water in the cartilage, making it
prone to cracking.
Joint damage can come in many forms, but the most common and main reason for joint
damage is inflammation. Inflammation is the breakdown and removal or foreign bodies, which
changes the chemical makeup of synovial fluid. Synovial fluid becomes thin and there is
destruction of the lubricating GAGs, causing cartilage to be easily damaged. The cartilage tries
to repair this damage by growing bone spurs, which only does more damage. This situation is
how arthritis is formed.
Arthritis is the primary injury that OJS are used to treat but there are other problems that
may respond to their use. These include degenerative joint disease, osteochondrosis, soft tissue
injuries and post-operative therapy after surgeries involving joints.
The goal of feeding OJS is to decrease inflammation, increase joint fluid and improve
There are two main ingredients in joint supplements; glucosamine and chondroitin
Glucosamine is a sugar molecule from which proteoglycans can be made. It also is a
precursor to GAGs and therefore may stimulate synthesis of collagen. It can be in one of two
forms; sulfate or hydrochloride, the latter being more common because it is believed to be better
absorbed. It also shows some anti-inflammatory signs.
Chondroitin sulfate (CS) is the primary GAG that makes up proteoglycans in joint
cartilage. It also inhibits degredative enzymes associated with cartilage breakdown, and has
general anti-inflammatory properties. However, CS is believed to be relatively indigestible. Some
studies have shown that only about 15% of ingested amounts are actually absorbed.
Most OJS include other additives, one of the most common being methylsulfonylmethane
(MSM). MSM is a source of sulfur that is necessary to strengthen collagen. Inclusion of other
micronutrients and antioxidants help the horse make best use of glucosamine and chondroitin
sulfate. Antioxidants may include blue green algae, Vitamin C, Vitamin E, magnesium, copper,
grape seed extract and omega 3 fatty acids. There are sometimes also natural anti-inflammatories
such as yucca and Devil’s claw, which can help slow the deterioration of the joint.
The latest studies have shown that it takes a minimum of 3 weeks for the effects of OJS
to be seen, if at all. As well, an average 1000lb horse requires a minimum of 10g of glucosamine
per day to slow the degradation of cartilage and help repair conjunction.
Some problems with OJS are that there is no enforcement of proper labeling and drug
claims. This means that the actual ingredients don’t always match what is on the label, and there
is no guarantee of purity of products. This is also an issue with much research currently under
way, so the effectiveness is still undetermined in the use of these products.
OJS are available in many forms, including powder, liquid, pellet, granular and paste.
There is no evidence that one form is better than others, it depends on personal preference. The
main issue is to purchase a supplement that contains a minimum of 10g of glucosamine per daily
Examples of oral joint supplements include Corta-Flx Solution which is a liquid form that
contains glucosamine, MSM and chondroitin. There is also Absorbine Flex +, a powder form
containing glucosamine, MSM and yucca. Others include Cosequin, Joint Combo, Fluid Flex,
Devil’s Claw Plus, and Performance One. There are unlimited variations to be found, all with
different ingredients and testimonials. The best decision is to consult your equine nutritionalist or
veterinarian, and choose what is best suited to your horse.
Jeremy D. Hubert, BVSc
Equine Health Studies Program School of Veterinary Medicine
David Ramey, DVM
Equine Advisor to Task Force for Veterinary Science
“Oral Joint Supplements: Cure-All or Expensive Fad?” by Stephen Duren, Ph.D.
Kentucky Equine Research