We use to have a fox terrier and we nick named him terrorist. he was a stray we picked up at our favorite fishing spot. he was looking pretty pathetic and he came up to me and sat down by me and would not leave. we got ready to go home and he came up to our jeep and looked so sad i could not leave him. and he was never potty broke we never did break him of peeing in the house. my husband and i both tried . we would feed him and water him and take him out side right after eating. we had a daily routine for him still no luck. we never had a problem with our other dogs . i know it's very discouraging but we just could not break him. best of luck
linda