I use Merricks, and Apple loves them...She is very small, so they last her a long time...They do have an odor, when you first get them, but after a few days, it's not so bad, and, who cares, if they like them lol...But about what they are made of, I believe it is the cartilage inside the bull's penis, and it's actually real meat/protein and not just hide, like in rawhides...Hide can swell in their stomachs and intestines and cause all sorts of problems, so I don't use them... |