I found this dog in a graveyard, probably waiting to die, with a huge open wound on it's backside 2 days ago. I've been feeding it, helping it regain it's strength but I'm concerned, the wound may get infected. What should I do? I live in a small town. We don't have vets that tend to canines here. How do I tend to the wound without hurting the dog or getting bitten myself?  