2 weeks have passed so I thought I would follow up on this, although it seems few are interested...
A couple of days after this post the bird took a turn for the worse. The effected area was bleeding from a crater that I suspect was pecked into it by the hens or by the rooster himself. I could see what looked to me like worms in the wound. These worms or maggots were about 1/2" long.
The bird started losing color in his comb. It had changed from a bright red to a pale pink/grey hue. I started to think I needed to bring an end to this before he was to suffer much more. I really didn't think he was going to make it so I got my .410 from the closet.
It seemed to me that a 5 lb rooster (estimated) probably doesn't have that much blood to start with and this guy was dripping blood at a terrifying rate.
The next day, he had separated himself from the others and had taken refuge in the garage. I decided to get some better food for him as he was not able to forage like he usually does. I went to the feed store and bought " Game bird conditioning" food by FRM. I fed him every chance I could find him, as he was keeping himself scarce. Luckily I had a few days off from work and I could make sure he had food and water as often as I could locate him. When I did find him I could smell the infection, his feathers were soaked in blood, but he never lost his appetite, he kept eating, although it was not much, not like he usually did.
I should probably let you know that this rooster was a volunteer...that is to say one day about 5 years ago, he just showed up here. I don't know where he came from but I liked him immediately because he would always call the hens to eat before he did. If he found a lizard, or a a grass hopper he would stand next to it and call the hens over too it and let them have it.
I suppose this is typical behavior for roosters but I don't know as this is the only one I have ever encountered.
About a week ago he started to improve, the bleeding stopped and the outer shell of the abscess looked to be drying up and getting smaller.
Today I'm pretty confident that this problem is behind him, I think he going to make it.
I can post some pictures if anybody is interested.
I am think thinking that this may have been an the result a of an insect that was able to get under this rooster's skin and lay eggs. Not unlike a bot fly will infiltrate a squirrel's body . In this case the fly was not a single larva like a bot fly, but layed eggs more like a bottle fly.
This rooster likes to roost high in a tree, by himself. None of the other birds do this and none of the other birds have any issues.
I really have no idea but it seems to me the other hens would have had a similar problems if it was mites or a disease of some kind.
Anyway...I'm really glad I did not give up on him.