My one year old Peke has begun acting very scary when we are getting him ready to go to his crate for the night. Ever since he was a puppy we would wash him up and brush his teeth. Never much of a problem. Now he at times tenses up and gets this look on his face like something out of the Exorcist movie and growls. I've stopped trying to brush his teeth because he no longer likes it and has snapped at me. I thought that maybe he is just tired and wants to be left alone. He's up and about around 7am and goes in his crate around 9PM. He's very active during the day and doesn't take long naps.I'm puzzled as to why a lovable dog during the day can change like this. Does anyone else have this problem? I'd like to know what's going on with him? Thanks.