Sophia Yin, DVM  May 25, 2009 Question I am crate training my 4-month old Yorkshire Terrier to hasten his potty training. I take him out on schedule and he was responding during the first couple of weeks. I subsequently added an exercise pen into the mix so he can play safely without supervision. Lately, however, I noticed he no longer wants to do his business on his designated area and would now... [Read more]