My 10 yr old Akita/Pei mix was experiencing difficulty on rishing and a general slow down for an old, and fair big dog. We can tell a difference in his mobility if he misses a few doses of this product. Unfortunately, he is really picky, and doesn't want to take them, although my super senior "grand dog" adores the stage III chews. As with everything else I've purchased from Revival, the quality is great, and you can't beat the phone people for advice and cheerful attitude.