Transmission of marble spleen disease in turkeys and pheasants

Marble spleen disease (MSD) of ring-necked pheasants (Phasianus colchicus L.) was transmitted in the laboratory to pheasants and turkeys (Meleagris gallopavo L.) by oral, colonic, and intravenous routes of inoculation, using cell-free supernatant fluids of splenic suspension from birds with naturally occurring MSD. Gross lesions consisted of large mottled spleens, a lesion more prominent in infected pheasants than in turkeys. The only microscopic lesion and also the criterion of infection were the presence of typical intranuclear inclusions of MSD. Similar to microscopic observations in naturally infected birds was the presence of inclusions in cells of spleen, bone marrow, liver, lung, bursa of Fabricius, and intestine-associated lymphoid tisse (IALT) OF EXPERIMENTALLY INFECTED BIRDS. Ultrastructural examination of splenic cells with intranuclear inclusions from turkey and pheasant with experimentally transmitted disease revealed viral particles and inclusions morphologically indistinguishable from those observed in naturally infected birds. Results of viral isolation procedures in turkey embryo chorioallantoic membrane (CAM) and yolk sac, as well as in turkey embryo fibroblast (TEF) and turkey kidney cell (TKC) cultures, were negative. Serologic assay by agar gel immunodiffusion tests indicated cross-reactivity between splenic MSD antigen and spleinic hemorrhagic enteritis (HE) of turkey antigen. Lines of fusion were formed between the splenic antigen from naturally occurring MSD in pheasants, experimentally transmitted MSD in turkeys, and HE of turkeys, using the homologous serum antibody to each of the 3 antigens.