Chicken keep dying

[speedymacca]

I have recently bought 4 new chooks all still young not chicks but not quite pullets, 2 silkies 2 Rhode Island reds, both silkies and 1 Rhode Island Red have died, they had seizures and then died I don't know what has done this please help so I can prevent the other one dying, non of my other hens or my rooster are sick

 

[1muttsfan]

Sorry to hear that you are having problems. How do you house your birds? Are the chicks in with adult birds yet? Do they all eat the same feed? Where did the young birds come from, and how long have you had them?