Extrapulmonary silicosis in two water buffaloes.

Two cases of extrathoracic silicosis in buffaloes raised near a quartz quarry and suffering from clinically severe silicosis are described. The extrapulmonary changes were characterized by silicoconiotic nodules in the tonsils, mesenteric lymph nodes and spleen. A combination of energy dispersive X-ray microanalysis and scanning electron microscopy revealed that the mineral component of these lesions consisted mainly of silicon, aluminium, iron, calcium, magnesium, zinc, sulphur and potassium. It is concluded that domestic animals raised in polluted environmental conditions represent an important biological source from which helpful data may be obtained for assessing risks to human health and gaining new insight into pathogenetic mechanisms.