Yesterday I noticed one of my Silkie poult "slumped" over and "panting". When i picked him up liquid came out of his mouth. I brought him inside the house and placed him in a carrier cage. He had no interest in the hard boiled egg but did swallow when i syringed water down his throat. He also had trouble standing and could barley lift his head. He died sometime last night. Necropsy showed the following: Spleen- enlarged, pale Liver- pale, fryable no abominable fat keel prominent pasty vent lungs ok. he was kept in a separate "chicken tractor" with a Silkie sibling and an older Buff Orpington. So far neither have shown similar symptom. Other large, older flock is healthy. The Silkies have had heat lamp (weather is currently in 20s-30s) food 24/7 and electrolytes in water (they both have been drinking alot of water) however, neither of them would leave the coop area. Dont know if they cant walk up or down the ramp or what. First time owning Silkies and so far they seem a little "slower" then all of the other chickens i have had. any suggestions on what could have been the cause of death? Should i be worried about the other 2 chickens it was housed with? Thanks! here's a picture of the 2 silkies (including the one that died) a week ago with their "Auntie"