Lymphoproliferative disease of turkeys. II. Experimental transmission and aetiology.

The clinical and pathological features of a previously reported lympho-proliferative disease of turkeys were reproduced by inoculation of 4-week-old poults, and spread to in contact turkeys was demonstrated. From studies on the development of the lesions in inoculated turkeys, it was possible to assay the causative agent based on microscopic examination of early lesions. Poults were more susceptible to inoculation when 4 weeks old than to inoculation at 1 day old, and different strains of turkey varied in their susceptibility to inoculation. The causative agent did not appear to be antigenically related to avian leukosis virus, to Marek's disease virus or to reticuloendotheliosis virus. Preliminary characterisation studies indicated a virus with properties similar to those of oncoviruses.