My vet, who is not a fan of age specific diets, told me that he doesn't know of any food that actually has a therapeutic level of joint supplements in it. You'd probably get better results by putting her on a supplement, like glucosmine. I have several seniors who are getting stiff. I feed them regular kibble (Acana Premium) and give them a glucosmine supplement plus antler. (My father in law is an antler carver so he saves all the dust & chunks for me). Seems to work. Preacher & Sleet are both at least 12 now and can both get up on the couch without assistance.