Nutrition

Modification of metabolic responses for cholesterol and other lipids as a result of dietary methods or drugs has been extensively studied in humans and laboratory animals, and much has been published on this topic. However, less is known about this topic in small companion animals, such as dogs and cats. One of the reasons is that compared to humans, cats and dogs are typically resistant to coronary artery disease, myocardial infarction, cerebral vascular stroke, and atherosclerosis. Thus, they are rarely studied in regard to these disorders. Nonetheless, dogs are especially useful in the evaluation of compounds that lead to important discoveries of drugs for humans. Therefore, knowledge of canine cholesterol, fatty acid, and lipoprotein metabolism must be understood for these comparative purposes.

Human clinical studies and a recent meta-analysis7 have found that dietary supplementation with fish oil and fish oil-derived fatty acids (in particular omega-3 fatty acids) provides benefits for patients with rheumatoid arthritis. Although the pathophysiology of rheumatoid arthritis in humans differs from the pathophysiology of OA in dogs, both conditions have an inflammatory aspect that could be sensitive to omega-3 fatty acids. In 2 recent studies, the effects of dietary supplementation with fish oil omega-3 fatty acids in dogs with OA found that feeding a diet containing 3.4% to 3.5% omega-3 fatty acids improved some clinical outcomes and weight bearing. In clinical practice, many dogs with OA are treated long term with NSAIDs such as carprofen, and neither of the aforementioned studies9,10 examined whether dietary supplementation with omega-3 fatty acids would allow a decrease in NSAID dosage. The purpose of the study reported here, therefore, was to determine the effects of feeding a diet supplemented with fish oil omega-3 fatty acids on carprofen dosage in dogs with OA.