I have been having problems with potty training too since the weather has changed. The fall has brought wet damp grass and cold temperatures. It sounds like a lot of work but I leash Benny and take him out myself. He learned pretty quick that we weren't going in until he went and it seems to be working. Don't know if that helps, but worth a try. I'm dreading the snow though, won't want to go out with him then!
