What does Shep Mr. Bailes' dog do when James comes that really annoys him and how does James finally handle it?

Shep hides and suddenly jumps out at James and barks in his ear. James finally drags Shep's chain and bellows back at him and really frightens him. Shep is actually a softie. James is worried that he has broken the dog's spirit but is happy to see him at it again with a tinker a couple of months later.