You may have almost killed him. That had been happening to mine about the last six weeks or so until Tuesday when I was unable to revive him. I'm heart sick because he was such a great roo and so good to my girls. He was one of our own hatchlings. He'd look like he was going to sleep, his head would turn almost black and then when he came around, he'd be gasping for awhile.
We've had a terrible problem with mites this year and I'd been treating them all aggressively for that and parasites. The mites haven't been just the usual chicken mites because they are too small to see. They've invaded my home and everything else. Maybe they invaded his lungs and caused pneumonia or maybe he picked up a respiratory infection this winter. Either way his heart was affected.
I noticed the last 3 weeks or so the tips of his wattles had turned black. I started treating him with Baytril and putting neosporin on the wattles. He also had a bright read rear end which was one of the first things I noticed. That seemed to be improving so I wish I'd backed off a little on the handling and treating because the stress was too much.
Then again, I never vaccinated him so it could be some textbook case of a disease, I looked at cholera and aspirgillis because of the blackening and hemorrhaging. I wished I kept him on Sulmet early on (I started to but with the antibiotic it turned the water blood red and I freaked out). That was about two weeks before I started the Baytril in earnest.
Anyway, it's all so confusing. I would start your guy on a good antibiotic (and assume respiratory infection) and avoid turning him over or stressing him out until you can assess the situation. You might do the Sulmet too. Give it a good couple weeks. Unfortunately when they start showing signs they're already very sick.
Maybe someone here can chime in. My guy's red undebelly may have been unrelated. I thought early on it was a hygeine issue or maybe irritation from parasites. I'm just so sorry I lost him. My hens seem to be fine with the handling. I did notice the one other hatched here at home had just a tad of the red lesion on the underbelly (that's when I began to worry about the vaccinating).
Anyway, even though your guy looks big and strong, he's in a very delicate situation. It's odd someone else out there is going through the very same thing I went through this week! I think these respiratory problems can be very insidious and not always obvious. Which reminds me, I'd better start up again with some antibiotics.
