Canine Osteoarthritis: A Vicious Cycle of Inflammation and Pain (Part 2)
Osteoarthritis, by its very nature, is chronic, progressive, and potentially debilitating. Dogs with osteoarthritis can suffer significant loss of mobility due to the pain that accompanies the disease. While pain by itself is debilitating - causing the pet to favor the leg or body part that hurts and affects their function directly - it also leads to gradual muscle loss, contraction of joint capsules, and contributes to other physiologic changes that result in a decline in mobility and function.
There are multiple treatment strategies for pets with OA, but all lead to one endpoint – improving the pet’s mobility and comfort. By providing joint support, we can endeavor to improve the health of cartilage of the effected joints. By interfering with inflammation, we can reduce pain and its negative physiologic effects on the body.
Treatment will reduce pain, which will result in an increase in mobility. As comfort levels increase, continued treatment encourages muscle rebuilding and improved range of motion. This will further reduce pain and its negative physiologic effects.
There are several categories of treatments for osteoarthritis. The most effective treatment approach combines therapies into a multi-modal strategy. By attacking the problem from several angles it is possible to maximize the effectiveness of therapy while minimizing the risk of side effects.
Slow-acting disease modifying agents include a variety of medications and supplements aimed largely at improving joint and cartilage health:
- Adequan ® (a proteolytic enzyme inhibitor) is an injectable medication given in the muscle that can help reduce inflammation in the joint, improve cartilage health, and increase the thickness (viscosity) of the joint fluid. All of these changes lead to healthier cartilage and joints.
The products listed above are all relatively slow acting and are typically associated with few side effects. They involve minimal drug interactions, typically making them safe for geriatric pets that may have concurrent health problems and be taking multiple medications. Non-Steroidal Anti-Inflammatory drugs (NSAID) are tremendously useful in the management of osteoarthritis in dogs. There are several different NSAIDs currently approved by the FDA for treatment of dogs. Individual pets may respond better to one medication than another despite their similarity. The most common brands of canine NSAID's are Rimadyl ®, Deramaxx ®, Metacam ® and Previcox ®. The effectiveness of a NSAID is often evident after just a few days and is typically recognized by increased mobility, activity and comfort in the patient. These are available in flavored chewable tablets, non-flavored pills, and a tasty liquid, so daily administration is not usually difficult. It is important to understand that these NSAID medications cannot be combined or overlapped, or used concurrently with oral cortisone, aspirin, or other human anti-inflammatory products. Multiple NSAID drugs used together or with cortisone nearly guarantee severe, and potentially life-threatening, adverse side effects. Human anti-inflammatory products can cause tremendous problems in dogs and should be avoided altogether. While there are some basic precautions with NSAID use - avoiding mixing NSAID's and monitoring liver and kidney function periodically - these therapies are often the medications that have the greatest impact on OA and generate the most improvement of any single category of medication. We have exciting new products that fit in this category being introduced this year that may provide even greater benefits. Eventually, as the patient's comfort level improves, these medications can sometimes be reduced or eliminated once the chronic pain is controlled and restarted later if needed as the OA progresses. Adjunctive medications include a wide area of therapies for specific situations. Since chronic pain can lead to “wind-up” - a form of hyper-sensitization that exacerbates the original pain problem - specific agents may be prescribed to reduce or prevent “wind-up”. There are also certain medications that can reduce pain by affecting neurotransmitters. And, of course, there are opiate drugs that can be useful for situations when there is more severe pain. While oral cortisone or Prednisone is not an appropriate treatment for typical OA, it can be helpful when injected directly into a severely affected joint. Cortisone is appropriate for immune-mediate arthritis, a distinctly different form of joint disease from degenerate joint disease or OA. Monoclonal antibody therapy for the pain of osteoarthritis sits on the horizon now and may provide tremendous advantages over some of our current options. Hopefully we’ll see this in action by late 2017. Alternative therapies can be combined with any and all of the medications previously mentioned without concern for potential adverse side effects. The two most effective are acupuncture and laser therapy. Each can be used very safely even in pets with serious health problems that may prevent the use of other pharmacological therapies. For more details about how Laser therapy helps pets, see this page. Regenerative medicine is a newer therapy for OA which involves injecting Platelet-Rich Plasma or Stem Cells directly in the affected joint(s). The cells are actually harvested from the patient, so no foreign material is injected into the patient. The injection procedure is the same as with hyaluronic acid but it can provide much more dramatic and longer lasting response in advanced arthritis. This link provides more detail about regenerative therapies available for pets. Weight loss is critical in osteoarthritis patients that are overweight, even if they are not obese. Excess weight creates an unnecessary burden on painful joints and fat has an active role in contributing to pain. Recent research indicates that fat cells actually secrete hormones and inflammatory mediators that contribute directly to OA and inflammatory pain! Many pets can have improved mobility and function with just weight loss and exercise. In a study of dogs that were free fed vs. those fed a 25% reduced diet, the heavier dogs had a much higher incidence of hip dysplasia even though they were not considered obese. Exercise can be very helpful in improving mobility and function. Typically, the pain must first be mitigated and then judicious exercise and rehabilitation can be designed for a long term strategy to help the patient progress to a much greater level of comfort and function. Environmental modifications can be introduced to make it easier for a debilitated pet to navigate their environment. Throw rugs placed over tile and wood floors can be a huge help to providing traction. A roll of yoga mat material can be cut to size and is an inexpensive way to provide floor runners for excellent traction throughout the home. Steps or ramps can be used to help pets access favored sleeping spots and to get in and out of the family vehicle. Arthritic dogs often have difficulty rising from overly soft beds, so firm support is ideal. Thick orthopedic beds can help reduce morning stiffness in some dogs. For the more seriously debilitated pet, a Help’EmUp ® harness can be a very useful. An individualized treatment plan can be created for any dog based on the severity of their osteoarthritis, the joints affected, loss of function, environment and overall health status. It may vary from something as simple as weight loss and a joint supplement to a multi-modal therapy using treatments and strategies involving several therapy categories. While some degree of osteoarthritis may be inevitable with age, there are now many therapy options which help to minimize the negative impact of OA. Our dogs can retain (or regain) their mobility and live longer, happier, and pain-free lives through effective treatment strategies and proactive osteoarthritis management. Elizabeth F. Baird, DVM, CVPP, CCRT, CVMA Country Oaks Animal Hospital Steele Pain Management & Rehabilitation Center Download Article: Part 2
- Hyaluronic acid is a naturally occurring compound that has a direct anti-inflammatory effect in joints, with lubricating and cushioning to the effected joint. It is administered directly via an intra-articular injection at the joint, typically in a series of three injections over several weeks.
- Oral products containing glucosamine hydrochloride, chondroitin sulfate, and MSM (methylsufonylmethane) have been used as daily joint supplements to boost overall joint health. Unfortunately, in both the human and veterinary market, many of the specific products have not been studied objectively for proof of effectiveness. Worse still, analysis of some supplements has revealed the bottles do not always contain either the stated ingredients or amounts noted on the labels. As this is a constantly changing market, your veterinarian can provide you with the most current and effective recommendations on specific products.
- Omega 3 essential fatty acids can provide assistance when used as a long term treatment. The fatty acids help to relieve OA largely with their antioxidant properties. The effective dose for Omega 3 is much higher than that used for skin and coat condition.