Osteoarthritis (OA) is the number one cause of chronic pain in veterinary patients. Over the years, we have made significant progress in earlier detection and better management of osteoarthritis. In their piece, I will discuss a few new ideas leading to smarter management of OA.

 

Risk factors of OA are obesity, age, orthopedic injury, and genetics. *Early identification of issues that negatively impact joint health helps to mitigate the effects of OA. Besides a thorough veterinary physical examination, there are now screening tools for identification and monitoring trends. Osteoarthritis does not happen overnight, so it is important to routinely use screening and monitoring tools to show stability or progression of disease. Some useful veterinary and owner-derived clinical metrology tools to measure activities of daily living are: The Canine Brief Pain Inventory (CBPI), Canine Osteoarthritis Staging Tool (COAST), Liverpool Osteoarthritis in Dogs (LOAD), and the Cincinnati Osteoarthritis Disability Index (CODI).

 

Once diagnosed, important strategies in OA intervention include – usually first and foremost – *weight management. We know that adipose tissue (fat) is an inflammatory mediator; it has been shown that even small reductions in weight can result in reductions in OA lameness. Once weight management is succeeded, it is safer and healthier to embark on an exercise strategy. If embarking on an exercise plan while the patient is overweight, other tools need to be utilized (for example, underwater treadmills via rehabilitation therapy) to overcome stress and strain on already overworked joints. Parallel to humans, exercise increases weight loss and muscle mass to better support aching joints. In patients that have difficulty losing weight, there are new veterinary-formulated diets for metabolic weight loss.

 

Pain management is crucial to OA management. Luckily, there are newer, smarter ways of accomplishing pain control. *Non-steroidal anti-inflammatories and adjunct analgesics are very good ways to provide pain control while a patient is exercising or sometimes just trying to accomplish daily activities with compromised joints. As in any chronic pain disease, initial (joint) pain is protective, e.g. a limp or lameness forms to protect the injury leading to decreased mobility. However, over time, this leads to altered biomechanics of the body, which puts irregular mechanical stresses and strains on joints, cartilage, ligaments, and also reduces muscle strength (atrophy). This leads to a continued deterioration of articular cartilage with continued release of inflammatory mediators. As a result, pain will increase, cartilage with degrade, and osteophytes will form – all resulting in more joint pain. It is a vicious cycle.

 

More recent understanding of OA has occurred at the cellular and molecular level where inflammation begins. Proinflammatory mediators and genes in cartilage set the stage for OA.  Continued research in this area has led to the identification of several hundred genes associated with OA. This research led to the proven idea of *nutritionally managing OA with (long chain) omega-3 fatty acids, most specifically eicosapentaenoic acid (EPA) found in fish oil (to down regulate inflammatory genes).

 

Rehabilitation therapy is a cornerstone of OA management. There are wonderful in clinic modalities to be used such as therapeutic exercises, laser therapy, electrical stimulation, therapeutic ultrasound, massage, acupuncture, under water, and land treadmills and shockwave therapy – but these are not easily accomplished at home. One wonderful in-clinic and at-home tool is The Assisi Loop, which is pulsed electromagnetic field therapy (PEMF). *PEMF is an active electromagnetic waveform delivered by antenna that cannot be felt. The Assisi signal is FDA cleared in humans for the relief of pain and swelling and Assisi’s veterinary research supports the human data. The Loop works to enhance nitric oxide, which activates anti-inflammatory cascades and inhibits excessive proinflammatory mediators in tissues. Additionally, nitric oxide stimulates a second messenger molecule (cGMP) modulating downstream targets that increase cell proliferation, migration, cell survival, and enhances angiogenesis and tissue repair. Additionally, it enhances endogenous opioid release which leads to a reduction in opioid intake. So in addition to relieving pain, it works to heal tissues.

 

Osteoarthritis is not a new veterinary issue. However, recent strides in smarter management (indicated by *) have very much improved how we manage OA and the greater whole of our patients. Why is a smarter approach important? A study published by Kealy RD et al in The Journal of Veterinary Internal Medicine in 2000 showed that proper weight management not only delayed the need for OA (and other chronic disease) management and intervention by keeping dogs healthier, but it also extended the dogs’ lifespan, depending on breed, by over two years! That is impressive.