If you can, please supply some more info per the posting guidelines. This will help us figure out what's going on ~
------------------------------------------------------------------------------ From Emergencies / Diseases / Injuries and Cures posting guidelines:
Give us the following information. The more you tell us, the better we will be able to help you.
1) What type of bird , age and weight.
2) What is the behavior, exactly.
3) Is there any bleeding, injury, broken bones or other sign of trauma.
4) What happened, if anything that you know of, that may have caused the situation.
5) What has the bird been eating and drinking, if at all.
6) How does the poop look? Normal? Bloody? Runny? etc.
7) What has been the treatment you have administered so far?
8 ) What is your intent as far as treatment? For example, do you want to treat completely yourself, or do you need help in stabilizing the bird til you can get to a vet?
9) If you have a picture of the wound or condition, please post it. It may help.
10) Describe the housing/bedding in use
He is a brown leghorn that is about 6 months old. This is the first day I noticed the discolored comb but the tail feather problem we have been dealing with a couple of weeks. I have 9 pullets also and only one is having tail feather problems but I still haven't seen any of them fighting. She has a little bleeding around the tail feathers. The rooster has had 1 bleeding feather that I put a little pine tar on but that is the only treatment.
If you have a couple of birds with broken and bloody tail feathers- someone is probably pecking at them. Chickens are attracted to red/blood and will peck at wounds. Feathers when they are first growing in have a blood supply and may be pecked by a bored bird, a bird that has developed a bad habit, ect. Pecking and hurting each other can be a sign of stress (not enough space, poor nutrition ect).
The rooster's (and hen's) comb if injured will get a black scab. A pecked/bruised comb might look like what you are seeing. A photo might help.
What are you feeding and how much square feet per bird do you have, ie how big is the pen, and how many birds in it?
If the comb is turning purple and the rooster is acting sick (lethargic, getting skinny, eating less, sitting down, less crowing, mating ect) , then I would worry more about the color change to the tip. It is a very vascular piece of skin, so if there is something wrong with the circulation, the color can change pretty dramatically.
Mites and lice are very common and could be causing feather loss and malnutrition. They are tiny and can be hard to spot, but look very very closely at the skin around the feather shafts. They lay eggs on the base of the feather shafts.
Do a search on her to find treatments for mites or lice. They're common, and don't worry, I've been told they are species specific and won't hop onto you or your dog or cat (but they will to other chickens).