The Histopathology of Maedi

Abstract

The histopathology of natural and experimental maedi, a slow-viral pneumonia of sheep, was studied. The main histological features are chronic interstitial inflammation with dense cellular infiltration, hyperplasia of smooth musculature in alveolar septa, and slight fibrosis; peribronchial and perivascular lymphoid hyperplasia, and epithelial proliferation in small bronchi and bronchioles accompanied in far advanced cases by epithelialization of the alveoli. The histopathology of maedi bears a close resemblance to pulmonary diseases of sheep reported under different terms in various parts of the world.