Joint Health

by Stuart Nelson, Jr., DVM
Iditarod 2003 was successfully completed in a year when most winter events were canceled! We all faced many unknowns as the journey began. In spite of the numerous new challenges, one thing stayed the same. Our responsibility as stewards of these great animal athletes never changed. Excellence in dog care continued to be our highest priority.
Although the bizarre whether patterns created many difficulties, the “can do” attitude of the ITC staff, mushers and volunteers, prevailed, and what a race it was! I would especially like to thank my trail veterinarians who endured seemingly never ending schedule modifications, including Plan A, B, C, D, etc.! They performed like a “well oiled machine.”
Speaking of lubrication, I thought it would be good to share some insight on joint care in this edition of the Runner. Many of you have heard of, and are actually administering/using, chondroprotective compounds. These are complex sugars commonly given to dogs, horses and humans. Their stated purpose is to help protect and maintain joint (synovial) fluid and (articular) cartilage. The three most recognized types of chondroprotective compounds given to dogs include polysulfated glycoaminoglycan (Adequan), chondroitin sulfate and glucosamine (Cosequin, Glycoflex, etc.). The major component of the polysulfated glycoaminoglycan is actually chondroitin sulfate.
These substances are believed to have two primary mechanisms of action. First, they are considered to be precursors (building blocks) for joint fluid and cartilage. In addition, they may also inhibit enzymes that are damaging to joint structures. Typically, such enzymatic activity increases in response to injuries and/or osteoarthritis. The primary rationale for their use is that these complex molecules are needed in much larger quantities than the body normally receives or produces, particularly in the case of joint inflammation.
Adequan is an injectable product approved by the FDA. Controlled research studies have demonstrated this medication to be efficacious. It is not a cure all, and some respond better than others. However, I can say that Irsquo;ve observed a number of dogs (various breeds), particularly elderly, who have had a very noticeable and rapid (2-3 days) improvement with treatment. One potential side effect is that it may slow clotting time, especially if administered at greater than recommended doses. Its use is contraindicated in animals with bleeding tendencies. Administration under veterinary supervision is highly advisable. For your information, ALL injectables are prohibited for use in dogs competing in the Iditarod.
The chondroitin sulfate and glucosamine products are given orally. A number of glucosamine formulations are available, including glucosamine hydrochloride, glucosamine hydroiodide, and glucosamine sulfate. These compounds are classified as “nutraceuticals,” a term meaning nutritional supplements. Such substances are not regulated by the FDA and are, therefore, less scrutinized as a group. Consequently, there is greater variation in quality and efficacy. Much ongoing debate exists as to how much of the chondrotin sulfate and glucosamine is actually absorbed through the stomach and intestines. The manufacturer (Nutramax) of Cosequin claims to have had the greatest amount of scientific review and support. Although not all are created equal, this class of neutraceuticals has benefited many animals, including myself! If no improvement is seen after 4-6 weeks of use, either try another brand or discontinue supplementation. At recommended doses, long-term chondroitin sulfate and/or glucosamine administration appears to be safe.