Coccidiosis caused by Eimeria tenella. This species of coccidia multiplies in the cecum, causing important lesions in the mucosa that lead to inflammation and bleeding (haemorrhagic typhlitis). The mortality rate is usually high, and it is advisable to review anticoccidial programs frequently, given the high resistance to chemical anticoccidials and ionophores, and to apply appropriate preventive programs that reinforce the local immunity of the intestine.