Thanks to everyone for your very supportive comments regarding our Doggy Saga. Nicky is healing up well (as you can see in the picture) and doesn't seem to be scared of dogs when he encounters one. He's asked where Xavier is a few times, too.
We've kept in contact with the shelter, where Xavier is quickly becoming one of the favorites, and the lady who runs things assured me he's doing great and will no doubt find a home quickly due to his sociable nature.