Pancreatitis caused by reovirus in guinea-fowl.

Pancreatitis caused by a reovirus was observed among 8- to 22-day-old guinea-fowls held under extensive conditions in groups of 10,000 birds. With the virus isolated from the affected birds the disease entity could be reproduced experimentally. Both the naturally affected and the experimentally infected birds showed depression, lack of appetite and weakness, followed by recumbency, opisthotonus and, occasionally, convulsions. A proportion of the survivors were retarded in growth and stunted. At the acute stage, the pancreas showed 2- to 5-fold enlargement and bright yellowish discoloration, was tense to the touch, and had haemorrhages and necroses both on its surface and within its substance. The main findings revealed by histopathological and electron microscopic examination included the degeneration and necrosis of secretory cells of the exocrine glands responsible for the secretion of digestive enzymes, and the intensive replication of viral particles in the cytoplasm of these cells. The subacute stage of the disease was characterized by an irreversible depletion of the glandular substance and reparative phenomena. The activity of amylase, trypsin, total protease and lipase significantly decreased in the infected birds' intestinal content; at the same time, in the injured pancreatic tissue the activity of these enzymes showed an increase. Hepatic deiodinase activity of the experimentally infected guinea-fowls underwent a significant decrease; parallel to that, serum T4 level increased and serum T3 concentration decreased.