My son came home and thought he was a dog

My son came home from school and started barking like a dog and crawling around like a dog. This isn’t the weird part. It’s the first thing he said when he came in the door that has me tripping “where am I am I at?” It felt like he was possessed or something like he forgot he was a human. I gave him a bath fed him and he’s back to normal. He remembers nothing