Not the main dog, but there are multiple dogs that still are killed throughout the book. Sometimes by other dogs, and once, several dogs fall through ice and drown.
There is one part in which the main dog gets beaten with a stick. In another, one of his friends gets devoured by wolves, though I don't think this would count as abuse.
This is kind of ambiguous. The dog goes free and gets to run around in the wild with a wolf pack, but it's heavily implied that his last owner, who actually took good care of him, was killed, so... do with that what you will.