I have a hen that is not using her left leg at all. She is a 6 month old coronation sussex. I have checked out her leg, there is no obvious break, sore or injury to her foot or leg. There is no heat emitting from the leg so there doesnt seem to be an infection. She kind of bumbles around but is able to eat and drink. She's been able to get in and out of the coop to the run (access is very low to the ground). She basically will just sit in the dirt or in the pine shavings. The others seem to be ok with her and are not showing really any interest in her so I hate to separate her from the others if I dont have to. I noticed her limping a few days ago and immediately checked her at the point thinking maybe she had bumble foot but that isnt the case and this has progressively become worse. Any advise? Should I cull her (I dont want her to suffer)?