Our 3 month-old chickens (2 Easter Egg-ers, 1 Silver-Laced Wyandotte and 1 Barred Rock) have had diarrhea for the last month or so. We have tried everything: changing their feed from organic to medicated, giving them yogurt and electrolytes in their water, and most recently-medication (aperol) for coccidosis--we completed this treatment. Some of their diarrhea has become explosive (seriously projectile) and we have also noticed some redness in some of the other firmer poop. We took a collective feces sample to our vet and the tested negative (for everything they usually test for). Now our larger chickens (in a separate coop but free ranging in a shared space) also have diarrhea. I know that there is a wide range of normal and have read up on every chicken poop blog post but this seems concerning, especially now that is seems to have spread . Any insight or advice? This is a photo of the big chickens poop (it has only become runny in the last two days) while the smaller chickens is completely runny.