International Omega-3 Learning and Education Consortium for Health and Medicine

Osteoarthritis (OA) is a devastating progressive chronic joint disease. Increased omega-3 (n-3) polyunsaturated fatty acids (PUFA) supplementation has been advocated as an adjunctive therapy for OA. Osteoarthritis progressively causes loss of articular cartilage and changes in the surrounding synovium and subchondral bone (1). During the development of OA there is a loss of the homeostatic balance between anabolic and catabolic pathways in the cartilage, driven by cytokine cascades and the production of inflammatory mediators (2). There is a growing body of data indicating that n-3 PUFA (eicosapentaenoic acid EPA and docosahexaenoic acid DHA) have anti-catabolic and anti-inflammatory properties in the joint.

The omega-6 and omega-3 essential fatty acids play an important role in the health of the skin and coat of dogs and cats. It is well known that linoleic acid (LA), a primary omega-6 essential fatty acid that is required in the diet for dogs and cats (1), helps maintain a healthy skin and coat. Without adequate LA, dogs and cats will experience dull, dry coat; hair loss; greasy skin and increased susceptibility to skin inflammation.

Although human and canine fetuses and neonates can desaturate and elongate 18-carbon omega-3 fatty acids (alpha-linolenic acid or ALA) to form their respective longer chain derivatives such as docosahexaenoic acid or DHA (22:6n-3) (1,2), it is uncertain whether the rate of synthesis is sufficient to meet the demands for optimal growth and development. In a study conducted by our laboratory, we found that, for puppies, the inclusion of modest amounts of DHA from fish oil in the diet during gestation, lactation, and suckling is more effective than high amounts of dietary ALA in improving electroretinographic (ERG) responses at 12-weeks of age (3).

Although dogs and cats are both mammals, they differ in many aspects of intermediary metabolism including specific pathways for fatty acid metabolism. Dogs have considerable capacity (relative to cats) to convert linoleic acid (LA), an essential omega-6 polyunsaturated fatty acid (PUFA), to its longer chain and more unsaturated derivative arachidonic acid (AA or 20:4n-6). Based on the dog's capacity to synthesize AA from LA, it does not have a requirement for AA (1). The rate limiting step for the synthesis of AA from LA is the delta-6 desaturase.

Each year, millions of dogs (5 to 17 million in the U.S.A.) are abandoned and euthanized (1,2). Among the various reasons for euthanasia, behavioral problems account for 50% to 70% of all terminations (3). Aside from the uncontrollable factors that contribute to this problem such as genetics, disease, and ageing, nutritional imbalance can also be a factor. However, since this is a controllable factor, it is among the easiest to correct.