Tissue from 15 weeks old turkey (X40; insert X400)
Description: Cerebellum. Meningial accumulation of fibrin, heterophils (viable and dead), and histiocytes. Cerebellar necrosis with heterophilic infiltration to the neuropil.
Insert: Blood vessels with septic thrombi (both in meninges and neuropil), fibrinoheterophilic inflammation, and numerous bacterial microcolonies primarily in meninges arachnoid.
Morphologic Diagnosis: Sever, diffuse, fibrinoheterophilic to granulomatous, necrotizing meningoencephalitis with intralesional bacterial microcolonies
Differential Diagnosis:Fowl Cholera - Chronic (Pasteurella multocida; confirmed by culture in this case)
Riemerella anatipestifer (ventriculitis)
Salmonella enterica (arizona and typhimurium)
Common route of infection: spread of infection from otitis media/interna to the meninges. Infection of the calvarium air spaces is a common associated lesion. Dr Z. Raviv