I have a few Golden Comets, couple leghorns & a few tufty cheek girls. Had the GCs first, then the 4H group gave us 2 leghorn hens & 1 rooster. (One of these had a dirty bottom constantly -but seemed fine as did the others for the first 6months). A neighbour hatched 15 mixed chicks for us last July. They all went in together in Oct/Nov. All was well until about Xmas. Moved them from their penned coop to a large barn for the winter. But one of the mixed chicks - rooster, seemed unable to stand & was getting picked on. I thought his legs were not strong enough for his big body. He passed away quietly one night. Since then I've been loosing about 1 every 6 weeks. One will just go off into a corner to be quiet, not eat or drink, then pass away in the night - now its getting more frequent. When I spotted one of the mixed chicks group I picked her up to separate her off from the rest & clear fluid came out of her beak&nostrils. From spotting one looking forlorn & wanting to be alone to them dying is 24-48 hours. I only have 6 girls left from 16. I clean out the coop daily & the waterer. THey have fresh straw (get cleaned out when one dies). They are on laying krumbs & veg / bread / fruit scraps. They free range within a large penned area. There was evidence of diorhea a while ago - but none now. I did clean out during the winter leaving the old straw & krumbs by the coop steps - cleared that away now, but its still 'soggy' - cant do much more than that... No question of poisoning. We are in the countryside - so have wild birds & squirrals, bats chipmonks all around. Bats & chipmonk are in the coop roof. The girls I have left all seem healthy & laying fine - I am wondering if there is a vitamin supplement that I could give them to help them fight any possible infections.Or should I get them an antibiotic or some kind of booster - I'll be heartbroken if they all go. I've got one little treasure with a slipped beak & no eye (beakey) as she was bitten by a mink when a chick 12months ago - but shes a survivor & just loves to eat & be scratched. Any suggestions would be welcome. Many thanks Lisa in Nova Scotia.