I lived in a very small apartment for over 3 years with my chihuahua Edie. She never had any issues with separation anxiety, I kept her in my bedroom while I was at work and she never cried or chewed anything up the whole time we lived there. I recently moved to a bigger apartment where I have two roommates and she has been so happy with all the space. She loves the living room and sitting on the couch, but I'm not comfortable leaving her in the whole apartment while we are all at work because she confuses rugs with wee wee pads and has had a few accidents. I did notice a few times when I would leave I heard her scratching on my bedroom door but figured she would calm down soon enough. Then the last few days I noticed all this black fuzz in my room, I discovered it was coming from her scratching at my shoe storage hanger on my door. She had scratched the door and shoe holder so badly that the bottom was completely falling apart and the shoe compartments were completely open. After inspecting her paws, her nails are all worn down on the sides and her little toes are so dry and scuffed up.
It breaks my heart that she has been scratching so badly at the door and is hurting herself. I was looking into putting tinfoil or double sided tape on the door to prevent it but I don't want her to hurt herself on either of those items and she may just scratch the wall next to the door anyway. I wish I could let her have free run of the apartment but I'm not comfortable with it and don't think I can trust her to not pee anywhere
she also doesn't usually cry or scratch when I'm leaving and my roommates said she doesn't cry while they are still getting ready so it has to be after everyone has left and she's been alone for a while.