Believe it or not a major difference in our ten year old Lab/Dobe mix (60/40). She has always been spry but during the past half year we noticed she wasn't bouncing around as much before breakfast... she used to hop backwards and high! Also noticed a few 'groans' when she laid down or got up. The vet suggested these as there were no other symptoms, nothing showed up that we could 'do anything about' otherwise. A week after starting (2 in the AM, 1 in the PM) these she was bounding about and the groans reduced by 80%... we think, anecdotally, that these made a big difference.