Hi Akari,
I found this study http://www.ncbi.nlm.nih.gov/pubmed/22805303 in which significant improvement was demonstrated through the use of a veterinary joint support diet. This study was double blinded and placebo controlled and used force plate analysis to measure the amount of weight the dog was willing to bear on the limb, so I do think joint diets have a place in managing arthritis. I can’t tell from the abstract which company’s product was used, but I don’t think it was Hills as their Omega 3 looks to be more ALA based.
I wouldn’t rotate the diet unless to one of similar EPA/DHA content and Omega 6/3 ratio otherwise I’d think the benefits would be lost. It takes time ( 6 weeks???) to incorporate the fatty acids into the cells and if you change off you may switch before any benefit would be seen.
With a Omega 6:3 ratio of 1.7:1 it may be difficult achieve that with supplementation of a standard diet. If your vet thinks it is appropriate I’d most definitely give this diet a trial of at least 3 months. It has a nice nutrient profile and nice ingredient line up!
