(OA) can occur from instability of a joint, chronic inflammation, or diseases that disrupt the surface of the articular cartilage and cause pathology in the joint. Treatment begins with diagnosis. Physical examination findings include muscle atrophy, loss of range of motion, increased joint size, and pain localized to a joint. Plain or stress radiographs can help to confirm a diagnosis, but the finding of abnormal changes on imaging does not necessarily correlate with OA. Treatment can be surgical or nonsurgical, with the latter being most common. There are several major nonsurgical treatment methods. The first most important method is weight loss. Studies in dogs with hip dysplasia have shown that a decrease of 25% of total calories can delay the onset of OA in dogs prone to hip dysplasia. The target body score for dogs with OA is 4 to 5 on a 9-point scale. The second most important nonsurgical approach is physical therapy and increased daily activity. Exercise restriction may be needed with inflamed joints. The third is medical therapy to decrease inflammation. Drugs to focus on are NSAIDs to inhibit the cyclooxygenase-2 enzyme pathway (COX-2 inhibitors). NSAIDs should not be used with steroids. Owners should be warned to stop the drug if the dog develops vomiting, diarrhea, or loss of appetite. Additional nonsurgical treatments are foods that are high in omega-3 fatty acids (eg, Prescription j/d Canine; Hill's Pet Nutrition). Chondroitin sulfate and green-lipped mussel are 2 popular nutritional supplements that are often used in cases of OA. These agents, which historically have been called chondroprotective agents, are now more commonly referred to as disease-modifying osteoarthritis drugs. There is less concrete evidence that these supplements are beneficial in OA, but they continue to be used because they seem to be safe and have the potential for benefit. Pain relief of OA can be provided by use of such drugs as tramadol and COX-2 inhibitors.

COMMENTARY: Untreated OA is painful and debilitating and can greatly diminish the quality of life of dogs. Education is critical in making clients understand that management is multifactorial, involving diet, lifestyle changes, and appropriate use of medication.