Management of Canine Osteoarthritis by Alison Ukockis

Introduction

One of the most common sources of chronic pain in canines is known as osteoarthritis. This condition is defined as a degenerative joint disease; and its high prevalence is not restricted to geriatric dogs alone. In fact, per a radiographic study, canine osteoarthritis was shown in 40% of dogs ranging from just 8 months of age to 4 years old. Contributing factors to this can vary from breed predisposition, weight, nutrition, as well as other orthopedic diseases and injuries.

In order to effectively treat this prevalent disease, multimodal management is crucial. This approach includes a combination of therapies such as surgery, analgesics, weight management, physical rehabilitation, and joint supplements. As canine osteoarthritis is not curable, the intended outcome of this treatment plan is ultimately to slow the disease process itself, as well as to reduce pain and inflammation. While each therapy listed above contains its own health benefits, this article will specifically explore clinically tested supplement ingredients as well as their therapeutic value.

Understanding Canine Osteoarthritis

To better grasp how these treatments function, review of the pathophysiology of canine osteoarthritis is vital. This entails thinning of cartilage, loss of joint fluid, and formation of bony growths surrounding the joint. These factors will proceed to cause joint membrane inflammation, lameness, and pain as the cushion of the joint is deteriorating. Malformation during early development, infection, and trauma are all components to consider when determining the underlying cause of this disease.

Though this condition has the potential to affect dogs in their adolescent period, early discovery is not common. Symptoms are not typically exhibited by them until they are about 5 to 13 years of age (), which provides immense difficulty in regard to management. Progressive pathological changes have often already taken place, in addition to the obstacles of environmental variations, individual patient needs, and differing responses to therapies.

Due to these challenges, complementary approaches to medicine such as nutraceuticals are highly necessary.

Key Ingredients in Canine Osteoarthritis Supplements

Glucosamine is an amino monosaccharide and noted as one of many ingredients utilized in joint supplements. Its primary function entails synthesis regulation of collagen in cartilage, along with the potential for production of anti-inflammatory effects. This compound is often used in conjunction with chondroitin sulfate, as studies suggest that these produce the most success in symptom management when administered together with the aid they provide in cartilage formation.

Chondroitin Sulfate is a natural portion of cartilage and essentially defined as a sulfated glycosaminoglycan containing fluctuating disaccharide units. This acts as an inhibitor of damaging enzymes in cartilage and joint fluid, in addition to preventing formation of pro-inflammatory genes.

Continued investigation of clinical benefits is imperative, as the current evidence remains too challenging to decipher with its diverse components. Differing salt forms, active ingredients, manufacturers, strengths, and compositions used within the studies should all be taken into consideration.

Despite the lack of scientific backing, glucosamine and chondroitin sulfate are commonly recommended by veterinarians as a substitute to patients with NSAID sensitivities. There is presently not enough literature supporting an official therapeutic dose of glucosamine for dogs, however, Plumb’s suggests an accompanying dose of 15-30 mg/kg for chondroitin. Gastrointestinal upset as well as hypersensitivity are possible adverse effects associated with these nutraceuticals.

Green Lipped Mussels (Perna canaliculus) consist of eicosatetraenoic acid and are sourced from New Zealand. This specific type of omega-3 fatty acid serves to inhibit oxygenation produced by arachidonic acid, which consequently reduces inflammation and provides support to cartilage. Out of 7 studies performed, 6 of those exhibited evidence of symptom relief associated with canine osteoarthritis. One of the successful studies explored and showed improvement of each patient’s peak vertical force, which ultimately provides analysis of gait function. In regard to administration of green lipped mussels, the recommended dosing is 77 mg/kg daily. Confirmed adverse effects are unknown, though supplements that contain the extract of this acid have potential to cause gastrointestinal upset and skin rashes.

Hyaluronic Acid is a glycosaminoglycan that is also a significant portion of joint fluid as well as cartilage extracellular matrix. The main functions of this nutraceutical consist of enhancing movement as well as division of cells, along with assigning viscoelastic components and lubrication to the connective tissues. With these functions, antinociception and anti-inflammatory effects can take place. The two major routes of administration of hyaluronic acid include intra-articular and oral, however only the intra-articular formations have been tested with proven success in osteoarthritis management. In this study, lameness among the patients was reduced and a decrease in nerve impulse activity was shown. There is little to no evidence backing clinical benefit from oral absorption, except one experimental study that provided results for improved osteoarthritis biomarkers. Therapeutic dosing and adverse effects of hyaluronic acid are unconfirmed at this time.

Manganese is a chemical element that’s primary purpose is to assist in major biological processes such as bone formation. Clinical evidence for use of this element in osteoarthritis management is slim, as one randomized controlled trial exhibited results of no improvement in the patient’s symptoms. Therapeutic dosing and adverse effects of manganese are also unconfirmed at this time.

Omega-3 Fatty Acids consist of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and are classified as polyunsaturated fatty acids. The essential role of this fatty acid group is to decrease the inflammatory response that omega-6 fatty acids create as they are metabolized, thus providing anti-inflammatory effects. Randomized controlled trials have shown clinical benefit including improvement in overall mobility and function of the affected joints. The established dietary ratio of omega-6 to omega-3 is currently unknown, and potential adverse effects associated with use of this supplement are also unconfirmed at this time.

MSM (Methylsulfonylmethane) is an organosulfur compound that acts as an inhibitor for activity of activated B cells. Activated B cells are noted to create a pro-inflammatory signaling pathway, therefore MSM is responsible for anti–inflammatory effects. While experimental studies may have been performed on animal models, evidence of clinical benefit remains undetermined. There is currently not enough literature to support a therapeutic dose for dogs and potential adverse effects associated with use of MSM are unconfirmed at this time.

Turmeric/Curcumin is a perennial plant that contains curcumin, originating from India, Indonesia, and Southeast Asia. Similarly to MSM, the curcumin component in this plant serves to inhibit activated B cell activity and its pro-inflammatory signaling pathway. Clinical evidence for providing benefit to canine osteoarthritis is limited and dispersed, however in one randomized controlled trial pain reduction was observed when turmeric was combined with hydrolyzed collagen and green tea extract. In regard to safety of use, side effects such as epithelial hyperplasia and facial discoloration were observed as elevated doses of curcumin were administered in animal specific studies. The official therapeutic dose for dogs as well as potential adverse effects are unconfirmed at this time.

Practical Considerations for Veterinary Professionals

Despite the many advantages of each featured ingredient, patient safety is the number one priority in treating canine osteoarthritis. Ensuring safety of the patient can be performed in several ways, one of which being careful selection and consideration of each nutraceutical.

Supplements that have been clinically studied with beneficial results and those that carry extensive literature backing are the most trusted to administer. Another factor to be taken into consideration is whether the supplement has been approved by the National Animal Supplement Council (NASC) or not, as this verifies that the ingredients used in manufacturing match the product label. Since these supplements lack the industry regulation that medicine possesses, confirming that the NASC seal is present on the packaging is imperative. Furthermore, as with introduction of any new medicine or supplement, checking for any drug interactions is crucial in this multimodal management plan.

Client education is also a major component in successful multimodal management. It’s highly significant that pet owners are made aware of how each supplement functions as well as how they complement the other forms of treatment. Many pet parents will draw the conclusion that natural supplements will be the ultimate cure for their pets’ symptoms and that they will always work rapidly. It is the role of the veterinary medicine community to educate them on realistic expectations, including the gradual progression of symptom reduction, the emphasis on consistent administration, and the fact that this disease is not curable but has the potential to be successfully managed.

Conclusion

Canine osteoarthritis is highly prevalent among dogs of all age brackets, and is one of the primary contributors to chronic pain. Due to the diversity of these cases as well as the commonly late recognition of this disease, multimodal management has become the standard approach in providing symptom relief.

Introducing supplements into multimodal management for canine osteoarthritis is proven to be clinically beneficial. A vast majority of these supplement ingredients produce anti-inflammatory effects that not only complement medicinal approaches, but also lifestyle changes. Clinical evidence and scientific literature should always be examined when forming a selection for each nutraceutical, and ongoing research will allow for a broader selection for future canine patients.