My 4 yr old mini schnauzer is vocal and barks a lot, especially when someone is at the door. when my husbands’ son comes in his behavior changes and he growls, barks A LOT, and shakes, with his ears back. when the boy approaches him he growls and runs to hide. He always growls when the boy comes into the room. He approaches other dogs and strangers after a warning or announcement bark, and he wags his tail. I believe the boy may have done something to him (he does not like the dog). But my husband thinks the dog is just nuts. what do you think? The boy denies anything.