Naturally occurring clinical reticuloendotheliosis in turkeys and chickens.

Outbreaks of clinical reticuloendotheliosis (RE) were observed in a turkey flock and two pullet flocks. Clinical signs in turkeys included sleepiness, weakness, anorexia, diarrhoea and reduced egg production. The pullets showed severe emaciation, loss of back feathers, anorexia and diarrhoea. Fifteen out of 54 turkeys died before the flock was killed. One pullet flock suffered 20% mortality while the other had an average daily mortality of four to six out of 2000 birds for 9 weeks with a total mortality of 16.4%. Necropsy of the dead turkeys and pullets showed neoplastic nodules or grey foci in the internal organs especially the liver, intestines and spleen. Histopathological sections of the organs had proliferation of reticular cells with necrosis of the parenchyma and focal lymphocytic infiltration. RE virus antigens and precipitating antibodies were detected in the serum samples collected from the birds. It was suspected that natural RE could be a more serious problem than earlier reported in some countries.