Page 168 - WSAVA2018
P. 168

 25-28 September, 2018 | Singapore
Therapeutic exercise is a key step in converting the osteoarthritic, overweight and sedentary dog to a lean, physically fit dog that is enthusiastic about activity again.
Diets specifically formulated for the dog with OAhave a practical place in the comprehensive management
of OA. Omega-3 fatty acids, a key component of these diets, appear to decrease joint inflammation, improve lameness and patient activity and reduce reliance upon NSAIDs.
Nutritional supplementation with so-called nutraceuticals containing chondroitin, glucosamine and manganese ascorbate have an apparent role in managing OA and preserving joint health. Combined, they function as building blocks to some of the normal constituents of joint cartilage and they decrease the effect of some of the destructive enzymes present within an osteoarthritic joint. Pragmatically, it is important to realize that these nutraceuticals are not subject to the same stringent regulatory guidelines as pharmaceuticals. In fact, one study showed that as many
as 84% of the human over-the-counter nutraceutical products vary widely in their composition and fail to meet their label claims. We recommend a high-qualityproduct that combines the glucosamine & chondroitin sulfate ingredients with avocado-soya unsuponifiables (ASU).
ASU decreases inflammation and, in human osteoarthritis trials, decreases pain scores and reliance upon non- steroidal anti-inflammatory drugs (NSAIDs). Combined, these nutraceuticals (also referred to as “joint protective compounds” [JPC’s]) have a role in joint health preservation and in the comprehensive management of OA.
NSAIDs decrease inflammation and, therefore, typically improve patient comfort and mobility in OA patients,
but should not be seen as contributing to joint health preservation. Rare adverse reactions most commonly involve gastrointestinal, liver and/or kidney function.
We recommend the medication be discontinued and immediate veterinary consultation sought if diarrhea, vomiting, melena, lethargy or lack of appetite is noted. Often, we recommend blood tests be performed prior to NSAID therapy and periodically throughout treatment.
Adjunctive systemic medicationscan decrease reliance upon NSAIDs or augment their effects in OA patients, but few of them have a role in joint health preservation.
Intra-articular (IA) injectionsof corticosteroids or hyaluronic acid have been advocated for osteoarthritic joints. CorticosteroidIA injection remains controversial with some studies demonstrating adverse effects on cartilagewhile others demonstrate symptomatic relief and chondroprotective effects. In dogs with OA induced by cranial cruciate ligament transection, triamcinolone hexacetonide, 5mg, IA reduced osteophyte size, cartilage erosions, and the histological severity of
OA structural cartilage changes with no electron microscopic evidence of increased cell degeneration
or death. Corticosteroid IA administration should be avoided immediately following arthroscopy because increased risk of septic arthritis. Intra-articular injection of hyaluronanhas been advocated for many species including horses and humans, but its effects on naturally occurring OA in dogs has not been extensively reported. Short-term symptomatic relief has been reported in a small-scale study of dogs with naturally-occurring OA following a two injection protocol (3 weeks apart) with a high molecular weight product. Hyaluron’s mechanisms of action may be transient improvement in joint lubrication and its longer lasting analgesic, pro-anabolic and anti-catabolic effects. Variation in molecular weight of the product, dosage, frequency of administration as well as species and OA model evaluated may account for the variation in reported outcomes. Disadvantages of its use in dogs may relate to its relatively high cost, the apparent necessity of repeated IA injections, and lack of robust efficacy data reported in dogs.
Biologic therapies such as cytokine therapy, stem
cell, and platelet rich plasma (PRP) therapy are gaining advocates, especially when more conventional therapies have failed to restore patient comfort and quality of
life. Upset of the critical balance of pro-inflammatory cytokines and anti-inflammatory cytokines is well- recognized in the pathogenesis of OA. Conditioning
of autologous serum from a whole blood sample has been used to stimulate the production of interleukin receptor antagonist protein (IL-Ra), IL-4 and other anti- inflammatory cytokines. Intra-articular injection of this autologous conditioned serum has resulted in significant clinical and histologic improvement in OA-affected joints. To circumvent the need for repeated IA injections, viral vector gene transfer technology has been employed
to obtain sustained levels of IL-Ra. This approach has resulted in elevated intra-articular expression of IL-Ra, significant improvement in clinical parameters of pain and disease, preservation of articular cartilage, and beneficial histologic effects on synovial membrane and articular cartilage in equine and canine osteoarthritis models. Research and development for improved viral vectors is underway. Stem cell therapy involves stem
cell isolation from various tissues including adipose and bone marrow and, in some instances, culture expansion. Injection of these cells into osteoarthritic joints may result in clinical improvement as compared to negative controls (sham injection), but few studies have evaluated this therapy compared to a positive control (current standard of care) therapy in the canine. In the absence of robust evidence for effectiveness over the current standard of care, the expense of stem cell therapy make it difficult
to justify for the majority of canine OA patients. PRP is defined as an autologous concentration of platelets in
a small volume of plasma. PRP contains a concentration of critical growth factors that are actively secreted by platelets to stimulate cellular proliferation, migration,

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