I have not seen a problem with loose bowels, but if you see it try just a half of a scoop. It could mean that he is getting too much Vitamin C. But if he has an injury he will need more Vitamin C. Yes Sherilyn Allen prescribed Finish line which is the same type of joint care for horses as this. She had told my friend about this when her dog tore his ACL. I like the Aniflex GL better because it has a higher % of Vitamin C. It is cheaper than Finish line too. But seems to be a better product.