SCHAUMBURG, Ill.—Osteoarthritic dogs that were fed foods containing high omega-3 fatty acid concentrations experienced less pain associated with the disease and greater mobility, according to a series of studies published in the Journal of the American Veterinary Medical Association (JAVMA).
The studies, published in the Jan. 1, 2010, and March 1, 2010, issues of JAVMA, included 274 dogs with osteoarthritis (OA) that took part in clinical studies at dozens of privately owned veterinary clinics and two university veterinary clinics. The researchers focused on three areas: the effects of omega-3 fatty acids on clinical signs of OA in dogs; the effects of omega-3 fatty acids on weight bearing in dogs with the disease; and the effects of omega-3 fatty acids on nonsteroidal anti-inflammatory drug (NSAID) dosage in dogs with OA.
The first of the randomized, double-blinded, controlled clinical trials (2010 Jan 1;236(1):67-73) evaluated the effects of a food supplemented with fish oil omega-3 fatty acids on weight bearing in 38 client-owned dogs with OA examined at two university veterinary clinics. Dogs were randomly assigned to receive a typical commercial food (n = 16) or a test food (n=22) containing 3.5 percent fish oil omega-3 fatty acids. After 90 days, the change in mean peak vertical force, which measures limb strength, was significant for the test-food group (5.6 percent), but not for the control-food group (0.4 percent). Improvement in peak vertical force values was evident in 82 percent of the dogs in the test-food group, compared with 38 percent of the dogs in the control-food group. In addition, according to investigators' subjective evaluations, dogs fed the test food had significant improvements in lameness and weight bearing on day 90. They concluded, at least in the short term, dietary supplementation with fish oil omega-3 fatty acids resulted in an improvement in weight bearing in dogs with OA.
The second study (2010 Jan 1;236(1):59-66) assessed the effect of food containing high concentrations of fish oil omega-3 fatty acids and a low omega-6/omega-3 fatty acid ratio on clinical signs of OA in 127 client-owned dogs with the disease in one or more joints. Dogs were randomly assigned to be fed for sic months with a typical commercial food or a test food containing a 31-fold increase in total omega-3 fatty acid content and a 34-fold decrease in omega-6/omega-3 ratio, compared with the control food. Dog owners completed a questionnaire about their dog's arthritic condition, and investigators performed a physical examination and collected samples for a CBC and serum biochemical analyses (including measurement of fatty acids concentration) at the onset of the study and at six, 12 and 24 weeks afterward. Dogs fed the test food had a significantly higher serum concentration of total omega-3 fatty acids and a significantly lower serum concentration of arachidonic acid at six, 12 and 24 weeks. According to owners, dogs fed the test food had a significantly improved ability to rise from a resting position and play at six weeks and improved ability to walk at 12 and 24 weeks, compared with control dogs.
The final study in the series (2010 Mar 1;236(5):535-9) suggested the dosage of the NSAID carprofen can be reduces in dogs eating a diet supplemented with fish oil omega-3 fatty acids. Client-owned dogs (n=131) with stable chronic OA received a standard dosage of carprofen for three weeks period (approximately 4.4 mg/kg/d (2 mg/lb/d)). Dogs were then randomly assigned to receive a food supplemented with fish oil omega-3 fatty acids or a control food with low omega-3 fatty acid content, and three, six, nine and 12 weeks later, investigators made decisions regarding increasing or decreasing the carprofen dosage on the basis of investigator assessments of five clinical signs and owner assessments of 15 signs. During the 12-week study period, carprofen dosage decreased significantly faster among dogs fed the supplemented diet than among dogs fed the control diet. The distribution of changes in carprofen dosage for dogs in the control group was significantly different from the distribution of changes in carprofen dosage for dogs in the test group.
"Many of us write off mobility problems in dogs as a part of the aging process," said author Dr. Kevin Hahn, director of research and chief medical officer at Hill's Pet Nutrition Inc. "These studies demonstrate that feeding a food containing omega-3 fatty acids to a dog with OA significantly improves mobility and quality of life. All three studies showed significant mobility improvement as assessed by either pet owners, veterinarians, or both."