A retrospective necropsy study of the ostrich (Struthio camelus) bursa of Fabricius.

A retrospective study of bursa of Fabricius from 90 necropsied ostriches from Florida farms was performed. Eighty-five bursas showed lymphoid necrosis and/or depletion, and acute to chronic inflammation. Rounded cytoplasmic inclusions were noted within bursal macrophages of 17 birds. Ultrastructurally, these inclusions comprised arrays of icosahedral virions with a diameter of 60 to 65 nm, suggesting possibly reovirus or birnavirus. Further work is needed to classify and determine the pathogenic significance of this virus in the ostrich.