Clean Run Magazine - May 2007 - 66

The high viscosity of synovial fluid allows for the cartilage surfaces of joints to glide upon each other in a smooth fashion. By injecting HA in a joint, some people consider this a so-called joint lubrication. This is why you may hear of HA as a “motor oil” for the joint. Numerous studies have been performed in the past decade to assess the effectiveness of HA as a treatment for OA. However, no clear understanding of how well HA injections perform has emerged. Early studies of HA were performed on too few patients and the follow-up period was limited to a short time. Some studies showed a benefit of HA injections, primarily in reduction of pain as assessed by patients, when compared to patients getting a placebo—a saline injection. HA as a therapeutic modality for the treatment of OA is based on the physiologic importance of HA in joints. Its therapeutic goal is to restore the viscosity, lubrication, and elasticity of joint hyaluronan, thereby decreasing pain, improving mobility, and restoring the natural protective functions of hyaluronan in the joint. Hyaluronic acid has been widely used intra-articularly (via direct injection into the affected joint space) in the treatment of OA in animals and humans. Intravenous HA has shown significant results for the treatment of OA in horses. The mechanism by which HA produces beneficial effects remains controversial. Possible mechanisms by which HA may act therapeutically include 1) providing additional lubrication of the joint membrane 2) controlling permeability of the joint membrane, thereby controlling effusions (seeping of fluid into surrounding tissue); and 3) directly blocking inflammation by scavenging free radicals. Other possible mechanisms include renewal of the cartilage in the joint by promotion of cartilage matrix synthesis and reaggregation of proteoglycans. HA is well tolerated with no demonstrable toxicity and few side effects. Because it is injected directly into the joint, its onset of action is rapid. Administration of intra-articular injections range from a series of 5 weekly injections to three to five week intervals. To date, there is limited information in the literature regarding the use of intra-articular or intravenous HA for the treatment of OA in dogs. It is well established that in dogs, like horses and humans, HA concentrations and viscosity are altered in OA. It has been reported that dogs with OA, rheumatoid arthritis, and rupture of the cranial cruciate ligament have decreased joint fluid HA levels compared to normal dogs. It has also been reported that friction in canine joints was increased in the disease state, but was significantly decreased after the addition of HA. Most studies in dogs have evaluated the use of intra-articular injections of HA following transection of the cranial cruciate ligament. Dogs in these studies responded favorably to intra-articular HA administration and showed no systemic side effects from HA administration. Results showed decreased severity of OA (gross and microscopic degenerative changes), restoration of viscosity and elastic properties of joint fluid, and a direct cartilage protective effect. HA is also currently available in an oral form. Unfortunately there are no studies supporting the efficacy of HA in an oral form. At this time, due to the lack of data on oral HA, it is not recommended as a top joint protective supplement. Omega-3 Fatty Acids Specific omega-3 fatty acids, known as “long-chain” omega-3 fatty acids (docosahexaenoic acid, or DHA, and eicosapentaenoic acid, or EPA, both found in fatty fish, such as salmon), are often recommended in pets and in people because they have far-reaching benefits in the body. (Note: if you live on the West Coast, particularly in Washington state, please be careful of feeding your dog raw salmon since raw salmon can carry a parasite that can fatally infect dogs; see www.vetmed.wsu.edu/ClientED/salmon.asp.) These fatty acids are very well known for protecting heart health but also support the brain/nervous system, the kidneys, skin health, the immune system, and the joints, which is especially beneficial in performance dogs. A recent study performed by Hill’s Science Diet Company fed one group of arthritic dogs a regular diet and a second arthritic group were fed a diet with a large increase in omega-3 fatty acids. At the end of the six-month trial, the dogs fed the omega-3 fatty acid supplemented food showed improvement in their ability to rise from lying down and a decrease in overall lameness. The omega-3 fatty acid diet appeared to decrease the inflammation in arthritic joints and decreased the amount of damaging enzymes in an arthritic joint. Foods supplemented with omega-3 fatty acids are just one of many products containing omega-3 fatty acids. They are also available in capsule and liquid form to be added to the regular diet. DHA (an omega-3 fatty acid) supplementation has also recently been shown to improve learning ability in puppies, so administration of a long-chain omega-3 fatty acid product, such as the high-potency natural salmon oil supplement Welactin, may prove helpful both during training and in maintaining good joint function. t has been well established in the literature that SADMOA agents are safe, able to cross into the joint, and modify the painful clinical signs associated with human and animal OA. Unfortunately, the majority of reports regarding these agents for the treatment of OA are still anecdotal. Since these agents are widely available and of very low toxicity, a trial use of them in a performance dog with OA to improve quality of life, or to perhaps prevent future problems, is a safe course to take. To substantiate the efficacy of SADMOA agents under various conditions and in varied dog populations, more formal veterinary studies are greatly needed. D References The authors submitted nearly three pages of scientific references to accompany this article, but we were unable to publish them because of space constraints. If you would like a copy of these references, please write to editors@cleanrun.com and we will be happy to send you a file. Dr. Canapp, a Diplomate of the American College of Veterinary Surgeons, completed a combined D.V.M./M.S. at Kansas State University, an internship in small animal medicine and surgery at the University of Missouri, a three-year residency in small animal surgery at the University of Florida, and training in canine rehabilitation by the Canine Rehabilitation Institute. Dr. Canapp currently practices orthopedic surgery and sports medicine at the Veterinary Orthopedic & Sports Medicine Group (VOSM) in Ellicott City, Maryland, and acts as a consultant to local zoos, police K-9 units, agility, flyball, and disc competition dogs. See additional information about Dr. Canapp at www.vetsportsmedicine.com. Dr. Debra Canapp, a certified veterinary canine rehabilitation therapist and acupuncturist currently practices veterinary rehabilitation at the Veterinary Orthopedic and Sports Medicine Group (VOSM) in Ellicott City, Maryland alongside her husband Dr. Sherman Canapp. Dr. Debra Canapp currently lectures throughout the United States on current techniques in veterinary rehabilitation to veterinarians, agility groups, police, and search and rescue groups. I 66 Clean Run | May 07

http://www.vetmed.wsu.edu/ClientED/salmon.asp http://www.vetsportsmedicine.com

Clean Run Magazine - May 2007

Table of Contents for the Digital Edition of Clean Run Magazine - May 2007