I would like to start off by saying that I am very new to raising chickens. All of my chickens are about 7-8 months old... There has been no problems except for my sick rooster.. About two and a half months ago my rooster had gotten ill for the first time. I had broughten him to the vet because I was deeply concerned. He had a lost his nail on the back side of his foot, became very lathargic, would not crow or act in any way that he used to and he had a concerning limp with his right leg.( The foot where the nail had become missing) When I took him to the vet I was giving an antibotic and some pain medication, I was told that he had some sort of infection in his leg. The vet was not sure what sort of infection but thought it may have been because of the nail that he had loss. After two months of being on the medication he slowly had gotten better. Although his leg still didnt seem a 100%, his actions were fairly normal. Each day after my rooster had seemed to get better and better, to where I decided to put him back in the coop with the hens.(When he was sick I had him isolated by himself to recoporate.) The rooster was doing very well for about 3 weeks after I had put him back in the coop with the hens. Until one morning we had went to go check on the chickens. We noticed that the hens were "picking" on him once again.(First time he was sick the hens would bother him..pecking at his feathers.) Once we seen that we knew something was wrong. When I looked at him he was limping once again...not exactly like before though....His limp now is as if the right leg is paralysed... When we move his left leg he easily tightens his foot and moves his leg.(reflex) But when we try to have him move his right leg..it is as if he cannot feel it.. there is not reflex and it seems to be much cooler to touch. When holding the rooster his right leg dangles while the left one still moves.... As I went back to the vet, I was giving the same medication with the same response..some sort of infection..... I had been looking up all sorts of diseases that chickens may encounter and mareks has caught my eye..... Any response would greatly be appreciated. Thank you.