Swollen comb

[N-Hubb]

What's wrong with my chickens they all have swollen combs especially this guy

 

[Eggcessive]

That looks to be a bad case of dry fowl pox, a virus spread by mosquitoes that can last 3-5 weeks. The wet version, which involves lesions in the throat that have a potential to block the airway, is more serious. I would look inside the thoats of any birds that look very sick. There is no treatment for pox, although many will apply betadine/iodine to the scabs to help dry them out. Make sure they continue to eat well because it may become too painful. They will be immune to that strain of pox when they recover, and birds who haven't been exposed can be vaccinated in areas where pox is a big problem. Read about pox here:
https://www.backyardchickens.com/a/avian-pox-how-to-treat-your-chickens-for-avian-pox
http://www.hyline.com/aspx/redbook/redbook.aspx?s=5&p=35

 

[N-Hubb]

Thanks I really appreciate the help!