treating chicks for Mereks

[blueskylen]

Hi,

i have 2 broody hens sitting on who knows how many eggs. The last time i had a broody - only 1 chick hatched. it was a beautiful EE, and lived to be about 8 months old, then i believe it got Mereks, as her legs overnight became paralyzed - none of the other hens ( who I had purchased immunized from a hatchery ) became ill.

i am wondering how and what to use for immunizing if I get some chicks hatched out?

thanks