Basement Pooper— absolutely no reason for it.

We are at our wits end. Our rescue we have had for 2 years will not stop pooping and peeing in basement. We have a large property he can freely roam whenever he wants. He also gets a 2 mile RUN everyday. He loves hanging outside for hours at a time. When we leave we have to lock him up in the laundry room because he will go right to the basement to poop. Regardless of how much time he’s spent outside that day. Our puppy German Shepard can freely roam the house but our 4-5 year old rescue can’t.

Just this morning he had been outside all morning running and sniffing up things in the garden. I let him inside at his request and within 30 mins he went to the basement to poop and pee. We were all home. I just caught him when he came sneaking back up.

Please! Whyyyyyy!!!! Anybody have insight into this behavior? I’ve read through old posts that aren’t super helpful into the actual behavior of why he is doing this for no good reason. If we put a gate up he just jumps right over it. We live in a nice home I’m not going to double stack gate our stairs to the basement because our dog.