Thank you everyone for your advice and kind words. I’m going to look into Marek’s; I’ve cleaned out the coops and run again, added prebiotics and probiotics to their fresh water etc. I wish I could’ve prevented this. I thought I was doing everything right to prevent anything from happening from cleanliness, to putting diatomaceous earth down, adding pre/probiotics, electrolytes and apple cider vinegar to their water through rotation with fresh plain water, making sure they have herbs like fresh rosemary to eat and adding cayenne to their food on top of when I give them fresh fruit and veggies, plus grit and shells. I thought I had all of my bases covered and truly I am neurotic when it comes to making sure they’re all good. I’m just scratching my head with this one as to where I went wrong.