My hen that was survived the dog attack and hauled herself home 8 hours later was very bad. She had a large hole opening into her side behind her leg, many shallower puncture wounds to the leg and rear, and a head wound. I don't know how she got home looking like road kill.
She wouldn't eat for almost three days. She did drink, though. I made sure she drank with me watching, to get the antibiotic in her. I was flushing everything with Vetericyn many times a day and hoping. After about the three day mark, she started feeling a bit better, and eating the boiled egg I offered. She limped for about 2.5 months, and the scab over the really deep hole took 4 months to fully heal. She has a slight indention there and no feathers. She has a droopy eyelid on the right side, but I've tested for sight and it's apparently fine.
I really thought she was a goner, but I couldn't put her down without trying after she made it home. I have two chicks of hers out there right now. I hope they have as good of constitutions as she does.
Well this give me hope -- only I'm not using any antibiotics. I suppose I should.