Last Sunday one of my hens (approx. 6 months, buff Orpington) seemed to limp a little when she came out of coop, it was like she was avoiding the rooster & then she took off running to be with group. Figured I was paranoid, being very protective of my babies. Monday, more notable limp but I couldn't catch her. Tuesday, limp, 5 steps then sit for long periods.... Now I,knew I,wasn't being crazy so I immediately started to set up chicken hospital in basement. I noticed her right foot & lower leg were swollen. She was eating & drinking fine. Eyes are clear, breathing fine, good feathering, no mites, no lice, no change in eye color, no scab on foot. Wednesday I noted she wasn't eating & poop was very reduced, watery & she was lethargic. I started to syringe water into her. Thursday I bought meal worms to encourage her to eat, swelling seems slightly reduced, started her on the tetracycline mix antibiotics 2x/day per vet. Vet seems to be at a loss, tho he doesn't do chickens often (most in these parts just butcher them if sick). She ate only 3 meal worms with encouragement. Friday she seemed a little better, ate 12 mealworms, more poop (maybe 6 all day). Yesterday wings started laying to her sides, didn't eat at all. Today I allowed her to see her sister to remind her what chickens do, she just layer there & her sister stood by her side for 3 hours. She will army crawl to a corner. I'm now force feeding her & crying. Any suggestions? What have I missed? Is it time to give up?