Manufacturer’s dog supplement description: “Cosequin, the #1 veterinarian recommended retail joint health supplement brand, plays an important role in maintaining optimal joint function. Healthy articular (joint) cartilage is crucial to joint utility and Cosequin helps support cartilage matrix production and protects existing cartilage from breakdown. The Cosequin brand of joint health supplements has the right formula to suit your dog. Cosequin supports mobility for a healthy lifestyle in dogs of all ages, sizes, and activity levels.”
[tabs][tab title =”Overview”]Cosequin is a supplement for dogs produced by Nutramax that “plays an important role in maintaining optimal joint function” by helping to “support cartilage matrix production and protect existing cartilage from breakdown.”
The product contains glucosamine, methylsulfonylmethane and chondroitin sulphate.[/tab]
[tab title =”How It Works”]Chondroitin and Glucosamine are found naturally in the body and are both essential for the healthy formation of cartilage.
This supplement provides “extra ingredients” to assist with the formation of healthy cartilage, as in joint disease cartilage is produced more slowly and sometimes broken down more rapidly.[/tab]
[tab title=”Uses”]This supplement is given to dogs that are suffering from degenerative joint diseases such as arthritis. Humans with arthritis have been taking it for a long time, and many people report a helpful effect both in pain relief and having fewer symptoms.
However, most large scale studies on both humans and dogs show that it isn’t completely effective, although it does seem to assist with pain relief.[/tab]
[tab title =”Side Effects”]The main side effects of taking this product are gastrointenstinal, such as diarrhea. They are usually mild and will often go away.[/tab]
[tab title =”Dosage”]The product comes as tablets, with the number of tablets to be given determined by the weight of the dog. There is an initial phase where the daily dosage is higher, and then a maintenance phase where the animal is given a lower dose.[/tab][/tabs]
Nutramax Cosequin with MSM for Dogs
Chondroitin is normally found in cartilage, while glucosamine is a precursor to several substances also found in cartilage, as well as elsewhere in the dog’s body. Methylsulfonylmethane is thought to be an anti-oxidant, and is claimed by some researchers to be important as a dietary source of sulphur for pets [1, 2].
There is some evidence that glucosamine and chondroitin have some very positive effects on dogs’ joint health, but there is no incontrovertibly clear demonstration of this. The most common cause of joint dysfunction involving changes to cartilage is osteoarthritis, in which the cartilage is eventually worn away, leaving the dog with bones rubbing against one another and severe inflammation in the joints.
Relevant scientific data
A study carried out in 2007 on 35 dogs testing the efficacy of giving oral glucosamine hydrochloride and chondroitin sulphate to animals suffering from osteoarthritis showed some benefit in decreasing pain when using Synoquin SA (another glucosamine/chondroitin preparation for dogs) . Although the results were achieved a lot slower than using Carprofen (a non-steroidal anti-inflammatory drug for pain relief prescribed by a vet).
The above study also demonstrated that while pain may have decreased in dogs using Synoquin supplement, lameness and mobility of these pets were unchanged (but it did improve when using Carprofen). This study had some design limitations, and was sponsored by VetPlus Ltd, who markets Synoquin supplement for dogs.
A separate, larger study carried out in 2003  indicated no benefit in giving oral glucosamine/chondroitin to dogs suffering from osteoarthritis, but showed improvements in pain and lameness in animals given Carprofen and Meloxicam. There were also a few design issues with this study, which was sponsored by Boehringher Ingelheim (manufacturers of Meloxicam).
The results of the clinical trials looking specifically at NSAID treatment and supplement use for osteoarthritis in dogs show that Carprofen and Meloxicam have more success treating the pain and lameness associated with the disease than using glucosamine and/or chondroitin. Neither of the studies directly comparing treatments in dogs included a placebo group so there is no evidence of whether glucosamine and chondroitin have any effect at all compared to no treatment .
Larger clinical trials in humans – and particularly meta-analyses of a number of trials – also showed the NSAID treatment to be more effective for pain than glucosamine and/or chondroitin , with the latter no more effective than placebo on balance . It should be noted, however, that significant pain relief was reported just through the use of placebo alone, and that for some groups of people given the glucosamine and chondroitin there was a statistically significant reduction in pain (primarily those that were in moderate-severe pain at the start of the trial ).
Customer reviews from dog owners who tested the product (source: Amazon.com) are almost overwhelmingly positive, although some pet owners make claims that are not supported by the trials carried out on the related product. For example, one of the reviews states: “within 4 days my dogs were no longer lame.” However, in trials that showed a clinical effect of glucosamine, the results were not observed for several weeks ).
This just goes to show how careful and critical dog owners should be when considering customer reviews. It is likely that glucosamine products have a high “perceived placebo” effect, which needs to be controlled for, because the name is well-known and is advertised heavily as a human supplement.
Overall, glucosamine and chondroitin are safe to give to pets, with few reported side effects only at the dosage level, and even then, the most common side effect of glucosamine is a degree of stomach upset.
Why Cosequin works in protecting cartilage
Background anatomy: Cartilage is composed of a number of different cell types held together by their structures and by attracting forces between the cells. The cells are arranged in such a way as to be able to “attract” and hold a large amount of water, making cartilage effective as a lubricant and shock-absorber.
Around 70% of cartilage is water, and the remaining 30% is composed of two main cell types: chondrocytes (1% or less) and collagen (c 15%). The remainder is proteoglycan (c 15%) which is a glycosaminoglcan (GAG) molecule, attached to a protein.
Chondrocytes build and maintain cartilage, and will respond to injury or degeneration by increasing local synthesis at the site of the damage . Collagen fibres provide a “framework” that houses the other components of cartilage, and provide the cartilage with its tensile strength.
GAGs are large molecules, generally found on cell surfaces (throughout the body, GAGs have a number of functions in addition to being the base for molecules in cartilage) or in the extra-cellular matrix (ECM). The ECM is the space between functional cells, generally filled by a “scaffold” of long chain molecules which are highly water-attracting, and arranged in such a way as to fill a lot of the available space , providing part of the mechanism by which cartilage can absorb stresses and behave as a lubricant in joints.
Each Cosequin chew contains 600mg Glucosamine Hydrochloride, 400mg Methylsulfonylmethane and 300mg Sodium Chondroitin Sulphate.
Glucosamine is a monosaccharide which is a biological precursor to several molecules in the Glycosaminoglycan family, and as such is part of the process of synthesis of cartilage. Some researchers have found that supplementing with glucosamine can stimulate the catabolic reactions that rebuild missing cartilage and repair damage . Other studies have found minimal or zero effects consistent with glucosamine having no more effect than placebo. Glucosamine supplements are usually derived from the exoskeleton of shellfish for dietary supplementation, and so should not be taken by people or animals with an allergy to shellfish.
Chondroitin is a member of the GAG family. It is an important part of the ECM, as it is largely responsible for water retention and loss of chondroitin is commonly found in osteoarthritis. Most clinical trials  have found that supplementing with chondoitin lead to higher plasma levels of the molecule (as with glucosamine). If this is able to circulate to the required areas, there is potential for a clinical effect. However, cartilage is generally poorly vascularised, and so larger molecules such as chondroitin will only reach a damaged area relatively slowly.
MSM can act as a precursor to sulphur-containing molecules such as SAMe, collagen and glucosamine.
- Parcell S. Sulfur in human nutrition and applications in medicine. Altern Med Rev. 2002 Feb;7(1):22-44. [pdf]
- Nimni ME, Han B, Cordoba F. Are we getting enough sulfur in our diet? Nutr Metab (Lond). 2007 Nov 6;4:24. [pdf]
- McCarthy G, O’Donovan J, Jones B, McAllister H, Seed M, Mooney C. Randomised double-blind, positive-controlled trial to assess the efficacy of glucosamine/chondroitin sulfate for the treatment of dogs with osteoarthritis. Vet J. 2007 Jul;174(1):54-61. [pdf]
- Moreau M1, Dupuis J, Bonneau NH, Desnoyers M. Clinical evaluation of a nutraceutical, carprofen and meloxicam for the treatment of dogs with osteoarthritis. Vet Rec. 2003 Mar 15;152(11):323-9. [study]
- Study meta-review: Nutraceuticals versus carprofen in dogs with osteoarthritis. [study]
- Large-scale GAIT trial: Questions and Answers: NIH Glucosamine/Chondroitin Arthritis Intervention Trial Primary Study. [study]
- Wandel S, Jüni P, Tendal B, Nüesch E, Villiger PM, Welton NJ, Reichenbach S, Trelle S. Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ. 2010 Sep 16;341:c4675. doi: 10.1136/bmj.c4675
- Martin JA, Buckwalter JA. The role of chondrocyte-matrix interactions in maintaining and repairing articular cartilage. Biorheology. 2000;37(1-2):129-40. [study]
- Molecular Biology of the Cell. 4th edition. [book]
- Jörg Jerosch. Effects of Glucosamine and Chondroitin Sulfate on Cartilage Metabolism in OA: Outlook on Other Nutrient Partners Especially Omega-3 Fatty Acids. doi: 10.1155/2011/969012
- Adebowale A1, Du J, Liang Z, Leslie JL, Eddington ND. The bioavailability and pharmacokinetics of glucosamine hydrochloride and low molecular weight chondroitin sulfate after single and multiple doses to beagle dogs. Biopharm Drug Dispos. 2002 Sep;23(6):217-25. [study]
Disclaimer: The purported effects of the supplements or ingredients discussed in this article may, or may not, have been subject to rigorous scientific investigation. This article is an introductory document which is not intended to be a scientific review either endorsing or refuting the claimed effects of the supplements or ingredients. The information is NOT to be used for diagnosis or treatment of your pet. You should always consult your own veterinarian for specific advice concerning the treatment of your pet. The supplement has not been tested or tried by the author of this content.