Black proventriculus in Cobb 500 broiler breeders

The black proventriculus is a necropsy finding sign observed during post-mortem examinations of dead young chicks up to 10 days of age and due to variation in color of the affected proventriculus organ, it may be ignored in some cases, in particular when the disease occurs simultaneously with other well-recognized infections of two weeks old chicks. In late January 2018, several live and dead chicks with a history of an unusual increase in mortality showing no clinical signs but sudden dead were referred to the poultry clinic of Faculty of Veterinary Medicine, Urmia University, Urmia, Iran. General routine postmortem examination revealed color changes (light green to dark green color) in the wall of proventriculus together with some degrees of congestion in the lungs and liver of the dead chicks. Microbiology tests revealed that the causative agent was Escherichia coli strain O142 and histopathological examination indicated that the color changing of the organ was due to necrosis of glandular epithelium with locally extensive or diffuse hypercellularity by lymphocytes and macrophages with hemorrhages. In conclusion, black proventriculus due to E. coli strain O142 was responsible for the sudden death of young chicks and based on antibiogram, selective antibiotics should be used for the treatment of the affected flocks.