Welcome to YT!
I agree that you should take him to the vet to get his blood tested. It is not totally unusual for a yorkie to sleep alot. My yorkie will sleep all day long if I let her, but she also will play all day long if I want her too. It does concern me that Alastor is sleeping alot even when you do not want him to. I would take him to the vet, just to be sure! Alot of sleep although is one
yorkie trait.