Potty training and scared to go outside
Hello! I have an approximately 5 month old male pitbull who is very stubborn. It has taken a LOT of training to get him to go potty outside and to tell us when he wants to go out. He was doing excellent up until this morning. I went to let him outside like I normally do, wake up, walk to the back door and he sits down for me to put the lanyard on him. I normally would open the door and he would run out, do his business then back inside but this time he tried to run away from the door. It was odd because I had to hold him to put the lanyard on him and I had to place him outside. He just ran back up to the door. I opened it and stood with him for several minutes saying "Go potty!" and he finally peed then darted for the door again. I gave in and let him back in the house. (It was 5am when my husband goes to work) and Jack (the pup) crapped on the floor just minutes later!
Just tried to take him outside again at around 7:30am and he acted the same. I had to stand outside with him and he kept trying to run past me to sit by the door.
He's always been a very fearful pitty, scared of the wind blowing outside kind of scared but as he got bigger he's gotten brave. I don't know exactly why or what happened that made him so terrified to go outside. The night before he was perfectly fine with going outside! It makes me wonder if it was a bad dream he had and now he's scared because he thinks it really happened? I just don't know and it was already hard to potty train him the first time.
Does anyone have advice? Has this happened to anyone's pit before?
Additional info: he eats and drinks normally and sleeps and plays normally just like any other morning routine. The only difference is that the other day a brown dog came into our yard and scared him. I opened the door and the dog ran off. He has encountered this dog before and this didn't happen, so I don't think that was it.