I have 14 laying hens of various breeds and ages. Lately my 2 year old Sapphire Gem has had a droopy comb. I noticed a few days ago she has some nasty smelly diarrhea. She is a little lethargic is drinking and pecking the ground. Today 2 other hens of the same age have combs that are starting to droop. No diarrhea and they are bright and active. Any ideas? I'm picking up Safeguard and Corid tomorrow. They do free range and go into the woods.