Wed one of my silkie roosters lay down and wouldn't get up, we noticed little bugs all over him so we treated everything, the yard the Coop the birds, i changed all bedding, bleached everything, sprayed with pymethryn, put pour on ivermectin on all birds, used poultry dust in bedding, he died the next day. now today one of the hens is dead, they are 5 months old any ideas? I don't want to lose rest they seemed he althy