I picked up some chicks last weekend from a breeder. About half hatched 2/2, the other half 2/9 so they are currently 2 and 1 week old, respectively. One of the older chicks died just hours after I got them home (a 2.5hr drive). It lost all muscle control, started having seizures, chirped VERY loudly when not and died with its neck wrenched all the way back (as though looking at the sky) and both its legs straight out behind it, feet contorted. Classic symptoms of central nervous system failure. Another chick, also from the older group, started acting lethargic, not running away immediately when I opened the brooder, though it still ran when I reached for it and was eating/drinking some. I have noticed sneezing and scratching at the nostrils from the entire group. This morning I found the lethargic chick dead in the same position. Both chicks were blue. I do not know if there are wonky genes associated with blue coloring that can cause central nervous system disorders. I have ruled out cocci or Marek's due to symptoms and the chicks' ages, respectively. From an extensive search I have determined Newcastle disease (highly unlikely), Equine or Avian Encephalomyelitis, or aspergillosis as possible culprits. Considering the mosquito involvement and highly unlikely incidence of both Newcastle and either form of EM, I am leaning toward suspecting aspergillosis. This was the first brood of the season for the breeder and I have no way of knowing how thoroughly the brooder was cleaned before use. Antibiotics will weaken immune systems without positively impacting the chicks, so I have not given antibiotics at this time. I am trying to feed yogurt (they don't like it) and am using ACV in the water. Any recommendations for treating aspergillosis or other ideas of what this might be would be extremely appreciated.