I have a 4 year old who has not - up to a few days ago - gone to the bathroom in the house since she was a puppy. The routine in the morning and evening is the same. She meets me at the door. I strap on her harness and we go for a walk. She goes to the bathroom in the same spots outside.

A few days ago she started to pee inside at the door while I put the harness on her. She sits for me to put the harness on and she simultaneously pees. I don't understand why the behavioral shift. This is during the morning and evening, and has been occurring over the last few days.

She is not peeing anywhere else in the house. Only at the door when I'm putting the harness on.

Any insight as to why this is happening?