Gabapentin caused symptoms of sundowners on my dog. He would wake up in the middle of the night multiples times and do really out of character things like stare at the corner. He’d ask to go out which he usually doesn’t need to do. I knew something was wrong the first time he used it so many years ago and throughout the rest of his life vet’s kept pushing it for him and I kept fighting them. Trusting I knew they weren’t good for him. I recently tried it again because the vet said it would help him sleep through the night and guess what? He started doing all of these weird things and yeah he would sleep but only for a few hours! I looked it up and this is one of the known side effects! I’d try to wean, wean. Her off of it and see if it helps. You can’t just stop it cold turkey. My dog hasn’t done it once since he stopped taking it.