Hey brother sorry this happened. You need to know that dogs are stronger that what we think in the mean time any antibiotic creme will help, if you can wash it even better.
Let us know so we can SHOOT THE FUC!@× Dog that did this!
It's really not the dog's fault... might consider winging the owner! If it were me, I'd let animal control know about it so the not so responsible pet owner can get in the system... Hope all is well with your dog.