Levels of TNF, IL‐6, GRO‐α, IL‐1β and IFNγ trended upwards in NEC pups compared with shams and, with the exception of IL‐6, were significantly increased in NEC + Cl‐amidine pups compared with shams (P = 0.0317 for TNF; P = 0.0333 for GRO‐α; P = 0.0029 for IL‐1β; P = 0.0442 for IFNγ). Here, IL1B is linked to necrotizing enterocolitis.