Fowl pox is spread by mosquitoes. This seems to be specific to chickens.   Most of the wild jungle fowl seem to be immune to it.      Until a year or so ago, I would not see it at all in the jungle fowl.   Over the last couple of years I have seen some of the free roaming  jungle fowl chicks with it.   I keep my baby chicks in screened incubators so they are not exposed to fowl pox prior to them being vaccinated with the fowl pox vaccine from the feed store. Some people vaccinate their chicks at 3 – 5 days old. With the tiny breeds, like the Japanese Bantams, the chicks are so little and the double needles are so big, I just can’t do it till they are larger. So I keep the mosquitoes away from them. Just to let you know how prevalent the infected mosquitoes are, I have had un-vaccinated chicks in a warmed cage in my house 300 yds from the chicken yard and they became infected. Yet I didn’t even notice any mosquitoes in the house.

I have tried treating it, unsuccessfully except for one adult bird that got it.  Things I have tried are DMSO, warm compresses and cutting off the lesions.    I read something about people who have used chloroxylenol, concentrated iodine, and toothpaste painted on the lesions.   I hate to give up, so I will try these remedies

To vaccinate the chicks, you mix the contents of the liquid vial with the solid vial of the vaccine, then withdraw the blue liquid into a shallow container in which you can dip the double needle. You stick the dipped double needle through the skin part of the front edge of the chick’s wing. The bird squawks a little but quickly recovers.