You might put out a crate with blankets, and place food and water there, as well as under the bed where he is hiding, so he can get it without having to come out.
Spend time near his hiding spot doing non-threatening things, like reading a book. You can also toss him treats while you read. Don't make eye contact, or try to touch- he will come to you. Use something stinky and tasty, dog's can't resist stinky treats! |