I have used the halti on my rotty/borer collie it sort of worked but he hated it so much that he would try and get it off and would smack his head on the pavment and give himself bloody noses. Then when he got used to it he wouldn't do that anymore he just learned how to run backwards and slip it off. then one day i left it out and he chewed it into a million peices. so i guess he didn't like it. ha ha ha