Sick Chicken

[biffabear]

I have a chicken that has difficulty moving around , and one of its wings keeps spreading out . It is eating and drinking a little . Has been like this for a few days . Icannot see any sign of a wound . Any ideas what it may be ?

[biffabear]

[pumkinlover]

Are its legs splayed out?
How long have you had the chicken?
How old is it?

I am not expert but  we had chickens with Mareks disease a number of years ago. commercial flocks are vaccinated against it but these came from an unvaccinated flock.