I noticed my 4 week old Dominique hen acting sickly 4-5 days ago. She is half the size of the other hens but she does have some of her feathers coming in. She's looking very round but not getting any taller. I've seen her eat but not drink the water that I've put some antibiotics in. If she's not eating she stands under the heat lamp without moving - I've not seen her lay down in 4 or 5 days. We isolated her about 3 weeks ago because her vent was pasty and swollen. We had one chick die right before we noticed dominques swollen vent - we figured she had caught whatever that one had. Took her out of isoloation after 3 days when she seemed healthier. any ideas?