Yikes, sorry to hear that man. I totally know what that's like though. We have a really old dog (going on 15 years now), and her best friend (other dog) got out and got himself hit by a car one day many years ago. She's been pretty lonley since, so a while back we got a fairly young dog as well. My old dog is pretty small (terrier), and this new dog, although young was already bigger than her (prolly 3/4 lab, 1/4 shepherd). There was a little tension at first, but after a while they seemed to get along, playing together and sleeping together fine. However, we noticed some weird behaviour with the new dog that led us to believe that it had been abused before we got it (got it from the SPCA so we weren't the first owners). When playing, one thing I did was run up to it and stamp my feet by the dog. Both of my older ones had fun, jumping up and down, running in circles, barking etc, but when I tried this with the new dog it cowered into a corner. It also liked to bite too hard when playing with me too, not the friendly little nips normal with most other dogs. Every once in a while too he'd be too rough with our old dog. Then one day, out of the blue, it just up and locked its jaws around my little dog's neck and head. A quick boot to the ribs and both dogs were off to the vet, one for a $1200 repair bill, and one for a $100 needle... It's a shame too, but he could have done it to a kid. We asked the SPCA what to do and they said there was no real choice.
I hope I got the right thread this time