I need help. I have had several chickens die over the last few weeks. They seen to have 2 different problems. Some of them start acting sleepy, uncoordinated and won't eat or drink. They will also gasp with their beak. Those seem to die in a couple of days. If I can force feed and make them drink they sometimes recover. The other ones just start to limp, with no other symptoms. I have checked their feet and see no cuts, sores or swelling. They eat, drink and get along ok. The first on I thought was injured but died in about a week. Then several more started acting like that. I don't know what to do. My flock is getting thinner! Help!