Senior food made Blaze crazy. We attempted at 7, then 10, then 14. He ate it like his old food and would not stop for a second. He chewed everything, he had so much energy, it was worse than when he was a puppy. He was under everyone's feet, he was aggressive towards children, other dogs, cats, horses, pigs, chickens, sheep, and cows. He's turning 15 on the 10th and he is on regular lamb dog food. He has the energy of a dog his age, and he is not aggressive. So we are keeping him on it until he loses his energy level, but when he can run with a five year old border collie and poop him out… I think Blaze will be on it for a while...