I am very new to keeping chickens. I just started about 3 weeks ago. I bought 4 layer hens from a local seller and two 5 month old barred rocks from another. The 2 barred rocks were supposed to be a little hen and a cockerel but the rooster certainly doesn't act like a rooster and my neighbor swears he is a hen (an entirely different issue). All 6 birds have been getting along great and seemed happy and healthy. I enclosed my entire yard with poultry fencing and allow them to free range out there during the day while I am home. Yesterday I noticed that my "cockerel," who is usually one of my more outgoing birds, was standing off by himself under the coop and didn't seem interested in water or free ranging. Upon closer inspection, he seemed to be opening his beak a little bit and making a gasp/sneeze/hiccup type of sound. I caught him kind of easily and put him in a transport carrier by himself and took him to the front yard away from the other birds until I could figure out what is wrong or what to do with him. I immediately removed all of the bedding from the coop and completely disinfected it and added new bedding just in case. After a little research I thought it might be a crop issue at first but then when I got home last night he had a really runny/snotty nose and was foaming at the mouth. I syringe fed him some water just to help hydrate him since he hadn't had any all day and a little bit of plain yogurt. He is emitting a terribly foul odor. When I woke up this morning my entire garage smelled like someone had died in there just from this little bird. I began reading through the posts here and although I did not want to consider the option, it seems like culling is the best bet at keeping the rest of the flock safe. Part of me thinks that it is too late for my asymptomatic birds and they will begin to show symptoms soon too. I guess my questions are should I cull this bird? And if so, how? Is there a place you can take chickens to have someone else do the dirty work?