I’m sorry for your poor Roo, I really hope he pulls through, from my own expierience with hormonal ganders I can say truthfully the flap is worse than the bite so I hope his internal injuries aren’t to extensive.
Thank you. Golly is an experienced chicken killer. He goes for their head, wattles, face, comb, eyes, etc are all fair game. Last year he did enough damage to a submissive hen (instead of running she'd squat and take the abuse) she was unable to open her eyes for three weeks or so. I kept her in a kennel with a huge food and water bowl she couldn't miss. Once the swelling went down and the lacerations from his bill healed she was back to her normal self. Before this he unknown to me killed a young cockerel. I found him with his head crushed in the middle of the yard. I thought something had grabbed him while they were out "free ranging" in the fenced back yard. Golly had a little blood on his face, but he's always into everything so I assumed he'd checked the youngster out and gotten annoyed when it didn't run from him. After the damage to Duchess though he was locked up in a pen by himself. He did the same thing to Suede, but I caught it much sooner. Suede's issue I think was compounded by him spending the first day in thirty degree weather in the rain and then the three other male chickens (and possibly that turkey jake who is getting his big boy hormones and thinks he can take on an angry gander) took advantage of him being "off" to the point where he did that thing roosters do when they lose a bad fight and just give up. So Golly physically wounded him and shattered his pride a bit. The other young roosters went after him and he lost the last bit of confidence spark he had. He's getting minimally better each day. He's certainly better than he was when I got him inside.