We really need some advice, but first I'll set up the situation. It's a long read :(
We have a five year old male Corgi called Fortie. We got him as a three month old puppy and trained him up. By around six months he was fully house trained, no problems with anything like that. Apart from being stubborn, he was great! At the time we were living in a two bed room apartment.
Around the time he was…