I am having breathing problems with my hens along with crusty eyes, sneezing, etc. We have tried Vitamin C, antibotics, apple cider vinegar. I have had two die in two days. We are thinking about having an autopsy done on the last one ($340) but it could take up to two weeks and by that time I will have lost more chickens. The vet recommended B 12 in liquid form...it says 1-3cc but doesn't say how many times a day. Help.