I've had Marek's birds that were fine one day, limping the next and floundering on the ground in the classic Marek's, one leg forward, one back splits, and 2 days later they were back up on their feet as if nothing had ever been amiss. I've had others that have not done the splits but lost use of a leg and some have taken months to improve and others have deteriorated quite quickly and needed to be euthanized. There just don't seem to be any rules or normal course for this disease to progress. Every one is different.
I appreciate that these birds came from a hatchery. Do you have any other chickens from another source that you added to the flock. Whilst Marek's is pretty common and easily contracted, it is usually brought into a flock with birds from another source like an independent breeder or bird bought at auction/swap.....Just wondering if you added to your flock a month or so before this bird started exhibiting symptoms as that would lend weight to it being Marek's.
Thank you for chiming in. I've suspicion I've had Marek's in just a few of birds. A couple limped, but recovered. The other hobbled on hocks, so weak, appeared to be doing a split (although it may have simply been how it was laying), and then died.
Marek's is morphing as a virus so it is now very variable than the old fashioned split leg than death.
LofMc