Useless leg

[Smithnchickens]

I've got a chicken about 5-6 weeks that has a useless leg. Not sure breed, was a mix up at tsc. Had one other chick of the same at age 2 weeks that had it and died. It seems fine other than that leg. It eats, drinks and makes its way around our large coop. I have 24 other chickens that are completely fine all roughly the same age group. I give vitamin water and acv alternately every few days, purina starter grower. So with all that what should I do, if anything?

 

[oldhenlikesdogs]

Looks like Mareks unfortunately. The one time I bought chicks at TS some came down with Mareks too.