Some pictures of the wound would be helpful.
I would try to bring him inside and set him in a warm, dimly lit, stressful free area with feed and water provided. Dripping drops of an electrolyte along his beak would be good, or occasionally tempting him to eat soupy feed.
For the wounds, I would flush them well with some saline, trim feathers around the wound area, then flush again. Once you have a clean wound area, I would apply a coating of an antibacterial ointment such as Neosporin, or Preparation H.
Of course, since it's a dog bite infection is always a concern, so it may be good to start him on an antibiotic. You can aquire several antibiotics online in fish or bird form, such as fish amoxicillin, or Baytril 10%. The only problem is shipping may take a few days/week, so as an alternative you could go to your local
TSC, pick up some Penicillin G Injectable and use that instead. Not the most effective antibiotic by any means, but it'll prove better than nothing. You can find that here,
https://www.tractorsupply.com/tsc/product/durvet-penicillin-injectable-500cc
You'll also need 22 gauge needles. The dose for Pen G is 0.15m per pound IM, once a day, or every two days.