I lost two chickens last week and i have two more that don't look that great. The ones that died and the two I have in isolation all have/had poopy butts. The ones that dies got very lethargic and once they were dead or almost dead they had snot looking stuff coming out thier beaks. One of the chickens I have in isolation kinda acts egg bound but she does have the poopy butt. Any ideas what I could be?