Isolation of Marek's disease virus from Japanese quail with lymphoproliferative disease.
Sixty-one Japanese quail from eight flocks with problems of recurring outbreaks of lymphoproliferative diseases resembling Marek's disease (MD), were examined aetiologically. Gross lymphomatous lesions were seen in 17 of the quail and 11 out of 56 quail had MD virus (MDV) feather tips antigens. MDV antibody was detectable in only one of 22 quail. None of 9 quail had antibodies against reticuloendotheliosis virus (REV). No MDV was isolated from the total 42 materials of quail using cell culture technique. No REV and avian leukosis virus (ALV) were isolated from some of them. However, specific-pathogen-free chicks inoculated with the blood materials revealed MD. and four MDVs were recovered from them. The isolates proved free from REV and ALV. The isolates were placed into serotype 1 by the indirect immunofluorescent antibody test. These results indicate that MDV is aetiologically involved in the present outbreaks of lymphoproliferative disease in Japanese quail.