Ovarian infection in layers: Some laying or breeding hens have green, infected ovules in the necropsies. This pathology corresponds to an infection by enterobacteria,  usually vertically transmitted, that does not cause the death of the hens, which remain as healthy carriers. The most frequently isolated microorganisms are Salmonella, Pseudomonas, Proteus and E. coli, bacteria that produce SH₂ and type IV toxins, which remain in the liver and get spread locally, to the ovary, or systemically, to the other organs, causing a syndrome known as avian infectious toxic hepatoenteritis.