My housemate brought his 3yo dog to live with us a few weeks ago and in that time he hasn't warmed up to myself or our other two housemates. When the owner is home, the dog is happy and acts normally, but when we try to get near, he will start to growl and run away. We can pet him without him biting us, but when we do, it stays as still as possible and sometimes starts shaking. If we feed him a treat with the owner around, he will only take it if he's near the owner and will then just run away again.
When the owner isn't home, the dog keeps his head down and stays really still in a corner of the house. It growls if I approach it, but again if I get close enough, I can pet him even though he stays perfectly still when I do. I tried taking him for a walk, but if I pick up the leash, he won't budge and I'd have to drag him to get him to move. He also won't eat treats or food when the owner isn't around.
I'm not sure about the history of the dog other than that it was an only child and the owner had it since it was born. It seems like the dog must have had some traumatic experiences at some point, but not that we know of.
What can we do to get the dog to not be so afraid of us?