My buddy may be dying

The two big males are always separated since they got into a big fight, yesterday the big male,Hobo, slipped past me and attacked the other big male,Zeus, i couldn't separate them and could only let them fight it out. Both came out bloodied but it looks like Zeus took a worse beating.
I finally got him into the house because we have some pretty cold weather here in GA., he's in a spare bedroom/hobby room, he's laying on his side on a big dog bed but won't move, hasn't moved all night. This morning i had to hold a small bowl of water for him to drink, got a can of salmon and tried to feed him, no luck. He does wag his tail and will raise his head a little to lap the water, there's no way i can pick him up or move him, he's over 100 pounds. This is the dog i rescued from being chained to a doghouse 24/7 for years, he's not aggressive and gets along with the 4 other pups, man I hate losing him, he finally has a shot at a decent life. Any thoughts/experiences?