Personally, the only 'help' that I ever offer to wild herps is popping off leaches or ticks. If you want to do something for the animal, do it 'in field'. The more you touch, move, and stress a snake the worse it will be. The rat snake has to deal with the stress the infection is putting on its body and the stress of being captured multiple times. I would leave it alone....nature is nature....things get sick and die....animals eat other animals....it is just the way things are.

However, if you are going to attempt a rehab by removing the animal from the wild, I would suggest keeping it out of the wild. Once removed from the wild, the chances that it will thrive in the wild decrease greatly. Reptiles have routines and know of places where they find food/water/shelter in relation to their location (that is why you have found him in the same area twice).....once they are removed from that place and established in captivity.....when they are re-released into they wild...they have to re-establish in the wild by itself (which is alot harder than establishing in captivity). It would be sad for you to work hard caring for a sick snake only to die because its enviroment no longer supports it.

I find busted up herps all the time....they live in a rough world.....but the strong shall survive.