We suspected our young hen of having Coryza. She had all of the symptoms. After researching on the net, I read that I could give her a shot of pen. I hated to do this, but she was very sick and Duramicin in her water for over 10 days dad had no effect. I had given my roo pen before when he was attacked by a dog and it was no big deal and he got better quickly after the injection. I thought I followed all of the advice...my daughter held her in her arms an her back (this was easy because she loves to be held this way and always goes to sleep.) After she settled in I felt for her breast bone and went a little to the right and down so not to get close to her heart. I was pretty sure I was injecting into the breast muscle. I had about 4 ml. in the syringe. She didn't even stir when the needle went in but after I got about 2ml. in, she started squirming and then sat up and just went limp! My daughter was panicking and so was I. We couldn't believe what we were seeing! My daughter said, SHE'S GONE! Oh, no what did I do? I killed her! We were devestated! I called my friend and she said she could have had an allergic reaction. Is this what happened? Did I overdose her? Did I give the injection in the wrong place? What ever the answer, I feel horrible! My kids are still crying. They said it wasn't my fault, but I know it is. I get so frustrated that we cannot take our special pet chickens to the vet...to someone who knows what they are doing!