HEMORRHAGIC ENTERITIS OF TURKEYS AND RELATED INFECTIONS OF PHEASANTS AND DOMESTIC-FOWL - A REVIEW

Haemorrhagic enteritis (HE) of turkeys is an economically important vi ral disease of turkeys, not only because it causes high mortality and immunosuppression, but also due to increased slaughterhouse condemnati ons. The disease is characterized by haemorrhagic enteritis and necros is of lymphoid cells and a proliferation of reticuloendothelial cells in the spleen. In marble spleen disease (MSD), in addition to splenic changes, pulmonary congestion and oedema are also seen. Whereas spleno megaly in chickens (SMC) is characterized by lesions in the spleen sim ilar to those of HE and the pulmonary lesions of MSD. The causative ag ents of HE of turkeys, MSD of pheasants and SMC are serologically indi stinguishable group II Aviadenoviruses. All the three viruses can be p ropagated in lymphoblastoid cell lines derived from Marek's disease vi rus induced lymphoma in turkeys viz. MDTC-RP-16 and MDTC-RP19. The inf ection can be diagnosed by isolation and characterization of aetiologi cal agents, serological tests such as the agar gel precipitation test, enzyme linked immunosorbent assay and the use of immunoperoxidase to demonstrate intranuclear adenovirus-like particles in infected cells s hown by electron microscopy. The control of HE is possible by vaccinat ion using avirulent MSD virus of pheasants as well as avirulent or att enuated strains of turkey HE virus.