management of osteoarthritis in performance dogs
|osteoarthritis in performance dogs|
these are the questions that went through sally’s mind when she brought dia to see me this past may. Sally has three aussies, but dia is clearly her fiercest competitor when it comes to agility. we discussed retirement, knee braces, surgery, and recovery. neither sally nor dia were ready for leisure life. ultimately I performed a solo surgery to stabilize dia’s right stifle. dia recovered well with lots of hard work and rehabilitation therapy and won her qualifying PSJ by 2 seconds 14 weeks after surgery.
she went on to compete and place 10th in her class at the ASCA agility Finals. not bad for a dog we debated about retiring! now our focus has changed from not if we can get her back to competition, but how to maintain her there. the “X” factor, of course, is arthritis. dia had mild to moderate degenerative joint changes in the right stifle at the time of surgery. while her muscle mass is symmetric and she is running well, photographs reveal a different story. she slightly favors the right leg on takeoff over jumps. in addition, mild muscle tremors are noted after heavy exercise. subtle, but important clues to the underlying condition in her stifle, osteoarthritis.
What Is Osteoarthritis?in fact, osteoarthritis (OA) affects nearly one out of five dogs over one year of age in the U.S. (Johnston SA, 1997). development of organic agriculture as a result of joint stability directly indirect hazards to the joint, or shaded defects cartilage development. dogs that are elderly, obese, or that have had a long athletic career are more likely to suffer from OA.
in all animals, the ends of bones are capped with a hard but slippery tissue called articular cartilage. this material protects the bone ends by absorbing shock and reducing friction between bones during movement. cartilage derives its nutrition from the fluid within the joint called synovial fluid. natural structure the function of the articular cartilage can cause relative discomfort easily. however, the body is designed to repair itself, and why the body’s repair mechanisms fail and OA develops is still incompletely understood. Osteoarthritis is defined as the breakdown and eventual loss of
cartilage within a joint. Once the cartilage starts to wear away, the underlying bone becomes exposed, causing painful rubbing of bone against bone. with enough loss of cartilage, the joint falls on itself, leading to the loss of common form joint instability. the body’s response to the loss of cartilage and joint laxity is a thickening of supporting structures and production of bone spurs along the edges of the joint. these pieces of bone or cartilage can break off and float around inside the joint space.
the effect is like having a pebble in your shoe, though substantially more painful. the result is a vicious cycle of pain and inflammation, ultimately reducing the ability of that joint to fully flex and extend.
the early stages of osteoarthritis are often subtle and can manifest as limping, sensitivity to touch in certain areas, stiffness (especially after rest), and difficulty doing normal day-to-day tasks (rising, lying down, or climbing stairs). In performance dogs, it may be more understated, showing up only as a slower course the time or dropping a bar. these signs are often attributed to old age in dogs, but age in itself is not a disease. while there have
been no studies looking at the prevalence of OA specifically in performance dogs, one would expect an increased incidence in agility dogs due to a lifetime of training and competing over varying terrain.
X-rays are the most readily available and inexpensive method of confirming the presence of OA. unfortunately, by the time degenerative changes are noted on x-rays, it is nearly impossible to reverse the changes that have already occurred and it is extremely difficult to halt the progression of the disease. an earlier diagnosis can be obtained by retrieving fluid from within the joint via a needle (arthrocentesis) and examining that fluid under a microscope to help determine if inflammation is present. this procedure is quick and easy to perform under moderate sedation.
Options for Managing OA:
Frequently asked about the best way to prevent and treat arthritis. while most dog owners are familiar with non-steroidal anti-inflammatory drugs (NSAIDs), many are unaware of the alternative options for medically managing OA. Many of these treatments have few side effects and can significantly reduce the pain and dysfunction of OA. A vast array of alternatives are available and
those alternatives have just as many opinions about their potential benefits.
NSAIDs Nonsteroidal anti-inflammatory drugs are commonly used for the treatment of OA.
Examples of these drugs include Deramaxx, Etogesic, Metacam, Previcox, Rimadyl,
and Zubrin. These drugs are excellent at managing the discomfort associated with OA. in general, NSAIDs are safe if used and monitored properly. Unfortunately, all of these drugs have the potential to produce undesirable side effects, including gastrointestinal, liver, and kidney damage. in addition, the main function they serve is to reduce inflammation and pain (cartilage degradation), but these drugs do little to promote cartilage health (cartilage formation). So in our practice, we often recommend using NSAIDs to offset the trauma of competition by using them the day before and the day following a trial. if long-term administration is necessary, we titrate the drug to the lowest dose possible that relieves clinical signs. we recommend a 48-hour wash-out period between the use of similar drugs within the NSAID family and recommend routine laboratory work be performed every 4-6 months with extended use.
Glucosamine/Chondroitin glucosamine and chondroitin are some of the most widely used products on the market. they both are building blocks of the normal cartilage matrix. when given in combination, glucosamine and chondroitin sulfate reportedly support cartilage production and protect existing cartilage by inhibiting enzymes in the joints that break down cartilage. results of several studies support that their combination has a significant anti-inflammatory effect against laboratory-induced and naturally occurring joint inflammation.
glucosamine and chondroitin products are naturally occurring compounds, are safe to use and have few side effects (most commonly gastrointestinal upset). however, because these compounds are dietary supplements, label claims are not federally regulated. purity is dependent on the manufacturer and can vary among brands. choosing the right supplement can be difficult. when looking for a glucosamine supplement, several things should be considered.
• One is the formulation of glucosamine as hydrochloride (HCL) versus a sulfate preparation. both are well absorbed by the gastrointestinal system. However, glucosamine HCL is preferred, because it is a more stable compound and does not require additives. therefore, glucosamine HCL is 99% pure, as compared to the approximate 80% purity of a sulfate combination. thus, you need to administer less to your dog to get the same benefit, saving money.
• Another consideration when selecting a glucosamine-chondroitin product is brand reliability. For my clients, I often recommend products from a local company (Nutramax Laboratories in Edgewater, Maryland) because I am familiar with their products (Cosequin and Dasuquin). Nutramax has a strong in-house research and development team and independent studies support their products’ safety and efficacy. For brands that I am less familiar with, I recommend owners investigate the product on their own through internet review sites.
More recently, glucosamine-chondroitin sulfate products are being combined with additional anti-inflammatory agents. Nutramax laboratory's newest product Dasuquin is similar to its widely used product Cosequin but has the added benefit of avocado soybean unsaponifiables (ASU) and green tea polyphenols. These ingredients are reported to work in combination with glucosamine and chondroitin sulfate to lower the expression of inflammatory mediators. Methylsulfonylmethane (MSM) is another natural-occurring anti-inflammatory that is being added to supplements. These ingredients are thought to enhance the effectiveness of glucosamine-chondroitin and provide additional pain relief.
Essential Fatty Acids:
Fatty acids are found in many types of food and can be categorized as omega-6 or omega-3. While omega-6 fatty acids are not “bad,” they should be consumed in moderation, as excessive amounts of omega-6 fatty acids or a high omega-6/omega-3, the ratio is thought to promote the development of many diseases, including cardiovascular disease, cancer, inflammatory, and autoimmune diseases. On the other hand, increased levels of omega-3 fatty acids (a low omega-6/omega-3 ratio) exert suppressive effects on the development of these conditions. the perfect ratio of omega-6 to omega3 fatty acids has yet to be determined but is thought to be around 3-4:1 in the dog. Essential fatty acids (EFAs) are specific omega-3 fatty acids (docosahexaenoic acid, or DHA, and eicosapentaenoic acid, or EPA) found in fatty fish? the fish do not produce omega-3 fatty acids, instead of kneading accumulate them from either consuming micro algae or other fish that have consumed microalgae. the concentration of EFAs is, therefore, highest in predatory fish like salmon, tuna, and cod.
essential fatty acids act by replacing harmful arachidonic acid in the cell wall, thereby reducing inflammation. they may also block the expression of certain genes that perpetuate the development of osteoarthritis. foods supplemented with omega-3 fatty acids are available. you can also buy EFAs in capsule and liquid form to add to your dog’s regular diet.
Shellfish supplements have been used as a traditional remedy for arthritis in humans. The New Zealand green-lipped mussel (GLM), in particular, has been shown to have beneficial effects for the treatment of chronic mild to moderate osteoarthritis. GLM contains a unique omega-3 fatty acid, which is thought to reduce inflammation by blocking two important inflammatory pathways.
The thermal treatment of GLM has been shown to destroy its activity. therefore, the processing of whole GLM and incorporation of the GLM product into food products is difficult. it is most readily available as a freeze-dried powder or incorporated into a capsule. there is relatively strong data that daily doses of GLM are effective at reducing total arthritic scores and scores for joint pain and joint swelling after 6-8 weeks of administration. I typically will try GLM in patients that show minimal to no improvement in glucosamine/chondroitin. the brand I recommend is Glycoflex because it combines the benefit of GLM with glucosamine and chondroitin.
adequan is an injectable polysulfated glycosaminoglycan (PSGAG) available for use
in dogs. adequan canine is the only FDA-approved product of its type in the arthritis treatment market. polysulfated glycosaminoglycan is made from an extract from the lung and trachea of cows. the principal component present in PSGAG is chondroitin, and adequan has been evaluated as an effective treatment of OA in adult dogs with no local or systemic adverse reactions related to the drug observed. I often use adequan in conjunction with oral supplements during
periods of heavy activity.
The use of intra-articular steroids has been looked down upon in the veterinary community for many years. In fact, it is difficult to find a published dose for intra-articular use in dogs. Steroids are extremely effective at reducing inflammation by inhibiting major inflammatory mediators and may also have a protective effect on the cartilage matrix by reducing degradative enzymes. however, there is a concern that long term use may depress normal cartilage cell metabolism, composition, and repair.
Systemic side effects typically seen with oral administration of steroids (increased water and food consumption, increased urination, agitation, weight gain) are minimal with intraarticular use. In our practice, we generally reserve intra-articular administration of steroids for severe cases of osteoarthritis that are unresponsive to other methods of treatment. we do not recommend oral administration of steroids for the treatment of non-immune mediated osteoarthritis.
Stem Cell Therapy:
Intra-articular use of stem cells is a hot topic in veterinary medicine previously discussed in CR November 2008. Stem cells are isolated or cultured from fat collected from the patient and injected directly into the affected joints. while a direct understanding of how stems cells work in patients with chronic arthritis is not available at this time, preliminary research suggests relief of clinical signs is primarily derived through anti-inflammatory and immunomodulatory effects. Preliminary data on the use of stem cells for chronic OA is promising, but long-term clinical trials are needed.
So, Which Product Should I Choose?
What was once perceived as holistic and the novel has now become mainstream in the treatment and prevention of OA? Although many products are available, not all products are effective in all patients. Until randomized, double-blind, placebo-based studies are independently performed on a large number of patients, there will still be more questions than answers with regard to the best treatment of OA.
implementation should be part of a balanced plan of weight control, exercise, and NSAIDS when needed. I would recommend consulting with your primary veterinarian before starting your dog on a supplement. Your vet may offer additional insight and experience to help you choose the right supplement for your dog’s specific needs.