I don't want to get into everything, that's long winded. I have a hen (just turned a year old) who, for the past few weeks has been off on her own, quiet, almost seeming depressed. She seemed to have diarrehea. We cleaned her behind off once and she stayed clean so I assumed the diarrhea had passed. This past Saturday I noticed that she stayed in the coop instead of going into the run with the rest of the hens. Which I might add are all fine. My husband and I cleaned and dusted the coop that morning and she did not move from one spot most of the day. That night we seperated her from the rest of the flock by putting her in a box in the utility room in the coop. Gave her yogert and water. Sunday she was still alive and we ran to the store to buy whole milk yogert, wheat bran and buttermilk. Some of the things we read on-line that were good at stopping diarrhea She ate very little. Only what was placed on her beak. In the afternoon we washed her behind with water and I cut away almost all her feathers back there to get her all clean. Then we put her back in the box under a heating lamp. We decided to keep the light on her constantly. She drinks water when I hold the cup up to her beak. She eats very little. Her diarrhea is watery and BLACK!!!. very smelly, but then poo doesn't smell like roses. She's very thin. Her comb and waddles are pale and shriveled. She will stand if you push her a little and she will walk- it's not wobbly like she's lame. She's very tired. Sometimes closes her eyes and falls asleep with my hands right in the box. I called my vet who is not a farm vet but has his own chickens. He suggested tylosin or tetracycline. Any input would sure be appreciated. I have no idea what's the matter with her and how to get her over the diarrhea.