Adapted from an article that appeared on EquiSearch
Horse joint supplements work! We finally have some formal studies that back this claim up. However, "nutraceuticals," as these compounds are called, are not tightly regulated by the FDA, so "consumer beware" applies. Indeed, it's easy to get lost among all the products and their ingredients.
The best approach with equine joint supplements is to read the labels to make sure the product contains appropriate ingredients in effective amounts. NOTE: These are the recommended levels if each ingredient is being used alone. When combined, many ingredients are effective at lower levels because they then work synergistically with the other ingredients.
Glucosamine is the best-studied ingredient in joint supplements. The basic building block of all connective tissues, including cartilage, it comes as either glucosamine sulfate or glucosamine hydrochloride, both of which are effective. It's best to stick with either the manufactured pure glucosamine or shellfish sources.
Glucosamine relieves pain, sometimes in as short a time as 10 to 14 days. Studies have shown that it can slow cartilage breakdown and may encourage healing. An effective dose is 6,000 to 10,000 mg/day. The 10,000 mg dose is usually needed for horses that are being worked. This higher level is also recommended during the first week or two of any horse's treatment, known as the "loading" period, which helps speed up results.
Chondroitin sulfate is a major structural component of cartilage, bone, and tough connective tissues such as the whites of the eyes. The pain-relieving effects of chondroitin are not as obvious as with glucosamine, although some observers report that horses on chondroitin only seem to move more "fluidly" overall. Formal studies on chondroitin give mixed results, with its greatest benefit appearing to be prevention of further cartilage breakdown. An effective dose is between 1,250 and 5,000 mg/day.
Glucosamine + Chondroitin
Recent research shows that best results are obtained when using combinations of glucosamine and chondroitin, rather than using either substance alone. Many equine joint supplements now combine these two ingredients (among other things). What you will often find, though, is that a product may contain both ingredients, but the dosage of one, or both, is low compared to the individual dosages listed above. Your best bet is to use a combination product that supplies a full dose of glucosamine (for pain control) and as close to a correct dose of chondroitin as you can find.
Keep in mind that glucosamine and chondroitin are the cornerstones of any joint supplement program. Unless new research eventually shows something else works better, you should focus on those two.
An important component of both the cartilage itself and the joint fluid, Hyaluronic Acid has been available as an oral supplement. It is particularly good for controlling pain, heat and swelling. The gel formulations cost more, but seem to give the most rapid and reliable results. Dosage is 100 mg/day.
HA is also found in a variety of powdered supplements. Addition of as little as 20 mg to a glucosamine and chondroitin combination product may make a difference for some horses. In other cases, you will have to use the full 100 mg dose or even more. If your horse has not responded as well to glucosamine and chondroitin as you had hoped, this is a reasonable next step. You can get an idea of how your horse may respond by first trying a gel in addition to your regular supplement for a few days.
Avocado and Soy Unsaponifiables (ASU)
Avocado and soy unsaponifiables are plant fats that are normally protected from digestion and absorption in the intestinal tract but are extracted and purified by a special procedure. In an equine study where arthritis was induced by a surgical procedure, these substances showed a protective effect against cartilage breakdown in a group of supplemented horses compared to those not supplemented. However, they did not appear to have an effect on pain. Yet studies in other species have shown that the release of inflammatory substances is inhibited, while growth factors needed for repair and maintenance increase.
ASU is classified as a "chondroprotective" (chondro = cartilage). It is a slow-acting substance. You won't see results overnight. Effective equine dose is at least 1,200 mg/day.
Although it is still not clear how methylsulfonylmethane works, or what the long-term side effects might be, it is an effective anti-inflammatory. One equine study in horses with hock arthritis showed it takes a dose of at least 20,000 mg/day to be effective. MSM is added to many joint supplements but rarely in doses that high. To assess your horse's response to MSM, buy a pure MSM product and add that at varying doses.
Collagen is a protein that forms the structural framework for all connective tissues in the body, including bone and cartilage. Hydrolyzed collagen is collagen that has been purified and also broken down into smaller protein units for easier digestion and absorption. It has naturally occurring amounts of glucosamine, chondroitin and hyaluronic acid, but the benefit is believed to come from the connective tissue-specific protein and amino acids.
Collagen hydrolysates have been used to promote wound and ulcer healing, and most recently, as a treatment for arthritis. However, the dosages required to get this effect in people have been quite high, and a horse may need as much as 40,000 mg a day.
Cetylated Fatty Acids (cetyl myristoleate, or CMO)
CMO (sometimes marketed under the name Celadrin) has received mixed reviews. It may help with pain and protect cartilage in some cases. It works better when combined with therapeutic dosages of other joint support nutrients, but no studies have been done to compare the combination of CMO with glucosamine/chondroitin versus just the glucosamine and chondroitin alone. Minimum equine dose is likely to be at least 1,400 mg.
Vitamin C is essential for the health of cartilage and other connective tissues, but this is definitely an area where more is NOT better. Excessive amounts may even damage cartilage. No equine studies are available. The equine equivalent of a human dose found to have a mild effect would be 4,000 mg/day, but a horse's body is capable of manufacturing its own vitamin C, and this could be too high. A horse on fresh pasture is taking in about 1,000 to 2,000 mg/day of vitamin C from grass.
A variety of anti-inflammatory herbs are often added to equine joint supplements, but there's no guarantee the amount being added is enough to have any effect. These herbs are most useful for horses that continue to have pain despite adequate doses of other joint nutraceuticals. The list of herbs is a long one, but here are two of the most commonly used and their likely effective dosages:
• Yucca—3,000 mg/day of 10% saponin powder to 15,000 mg/day of 2% saponin powder
• Boswellia—500 mg/day of extract
Manganese is a trace mineral that plays a critical role in cartilage metabolism. It is required for the production of chondroitin sulfate in the body. However, if your horse's hay, pasture and grain are average quality, he is not only meeting his minimum requirements but probably getting a lot more manganese than he needs. With minerals, more is definitely not better. Avoid manganese entirely or find the lowest dose you can (25 mg or less) while still getting the other ingredients you're after.
Copper and Zinc
These minerals aren't included as commonly, but many equine diets are both high in manganese and low to downright deficient in copper and zinc. Copper plays a key role in connective tissue formation, and both copper and zinc are involved in one of the body's important antioxidant enzyme systems. If they are in the supplement, 50 mg of copper and 150 mg of zinc are reasonable and safe potshot levels.
• Don't wait until your horse is severely lame to start a joint supplement. Some changes may be irreversible.
• Start with a supplement that provides 6,000 to 10,000 milligrams (mg) glucosamine and 1,250 to 5,000 mg chondroitin.
• Hyaluronic Acid is most useful for acute flare-ups or for horses with persistent heat and swelling, which indicates ongoing inflammation.
• Avocado and soy unsaponifiables and cetylated fatty acids are both slow-acting ingredients that may protect against further cartilage breakdown.
TIP: Look for the NASC seal for assured quality and safety—and stick with research-based products! For example, Absorbine was one of the first companies in the industry to perform a clinical field study on joint supplements. Today, the company's Flex+Max Optimized Pellets contain guaranteed levels of glucosamine (10,000 mg) and chondroitin sulfate (1,200 mg in a special low molecular weight to enhance its bioavailability), as well as 5,000 mg methylsulfonylmethane (MSM), 150 mg of Hyaluronic Acid and 5.6 g. rice bran. Also included: 11g of flaxseed, 130 mg of Boswellia Serrata and fenugreek for increased palatability.