If you haven't yet, consider putting him on a proper raw diet. Oh, and do not get him neutered if you haven't yet. Intact is much healthier and live mich longer. There's a channel called Fenland Forager, he has a video of his twenty year old intact female, Lilly. She was fed a raw diet and had two litters. She was also a working dog, which is a very stimulating life for a dog. Oh, and they poop a lot less in a raw diet. A LOT less.