The sizing is not clear - it would have been helpful to know measurements for the different sized chews. My Whippet is a medium dog, so we bought a medium and I really think it's a bit too small for him. I bought one of these because I'd heard how good they are, but apart from the occasional chew, he really isn't interested. It also came flavoured, even though it doesn't say this on the website blurb - and I was trying to avoid giving my dogs artificial flavours. I won't be buying one again.