Pathology of Mycoplasma synoviae and other concurrent infections affected oviduct in commercial layer chicken

Abstract

Pathology of oviduct affected with Mycoplasma synoviae and other concurrent infections was studied. Eggshell apex abnormalities (EAA) outbreak was reported in ten commercial layer farms in Namakkal district of Tamil Nadu which was suspected for M. synoviae infection. Oviduct samples were collected to study the pathology of oviduct and for the molecular confirmation of M. synoviae infection and other possible oviduct infections viz. Mycoplasma gallisepticum, E. coli and Infectious bronchitis virus by specific PCR. Out of ten farm samples screened eight were positive for M. synoviae, nine were positive for E. coli, all ten were positive for M. gallisepticum and all were negative for infectious bronchitis virus. On post-mortem examination, EAA affected birds exhibited no gross lesions except egg bound and congested oviduct in few cases. Microscopically, oviduct revealed degeneration, necrosis and desquamation of lining epithelial cells and atrophy of tubular glands. Serofibrinous exudates in the lumen and marked infiltration of macrophages and heterophils were also noticed. These findings showed that Eggshell apex abnormality producing oviducts had combined infection rather than individual etiology.