I am a new Yorkie Mom. We are in the process of potty training outside. Archie needs to have a leash on. We heard about the deadly results of a collar (weak trachea). So, switched to a harness. Need to leave the harness on @ all times because he acts like we are killing him when we take it on & off. Is this OK to leave it on continuously? He doesn't seem to mind the harness. Anyone have any ideas? Thanks!