Sick Rooster, What should I do?

[Wills Chooks]

My Barnevelder Rooster has recently been really quiet and has just been sitting in the corner of the coop with his feathers fluffed. He also has a bluer than normal comb and seems to have bad ballance. He also will not move when you come close and he is normally quite flighty.
I hope someone has a solution to what this might be and for how to treat it

Thanks Will

ps. He is not a very old rooster

 

[Eggcessive]

A blue comb could be a sign of heart problems or not getting enough oxygen. His balance may be related, but could be from dehydration or a disease such as Mareks. Does he cough or sneeze, or gasp when he breathes?Can you look him over for any lice or mites, and try to get him eating and drinking? Wet chicken feed in a small bowl, tuna, or canned cat food might tempt him to eat.

 

[Wills Chooks]

I will do that right now and tell you how it goes

 

[Wills Chooks]

He doesn’t seem to have lice and he was stumbling around foraging and drinking a bit but his balance is really bad. He also doesn’t cough or wheeze.
is this going to be fatal for the chook or contagious?
Will