My two year old Yorkie has had a growling problem since about a year ago. It started with him growling when he had a bone or something to chew and so I took away the bones but now he will sometimes growl just laying down on a couch and if anyone moves he will start growling. When he does this he doesn't stop until he's ready, so ignoring him or acknowledging him have the same effect. He also growls when we bathe him and dry him off. I love my dog but these characteristics are extremely difficult to live with

I just don't understand what makes him act this way!