newbie trying to figure out what to do after a merek's victim

[runswithroos]

Alright so out of a flock of 6 chickens (RIRs and Leghorn stayed in a big coop, EEs live in an "apartment") the "sickly" RIR was put down last night because of most likely merek's. Paralyzed, tumor, not pooping but eating but not very much. I found her in the classic merek's position-one leg in front other in the back, wings dropped. No other hens (or my roo) have gotten it yet and they all were vaccinated. By the way the RIRs and Leghorn are almost 4 and the EEs are almost 20-25 weeks

 

[runswithroos]

*****UPDATE!!!*****

my hen didn't have merek's. she was internally bleeding

 

[IowaHeritage]

SO whatever happened ?????