Bovine melioidosis in South-Eastern Queensland.

Acute fatal infection with Pseudomonas pseudomallei caused pneumonia, placentitis and endometritis in a pregnant cow. Pneumonia was also present in the foetal lung. Mononuclear cell response with extensive karyorrhexis occurred in maternal and foetal lung and the same cellular pathology, but with diffuse distribution, was responsible for plaques on the endometrium. A more chronic disease with encapsulated caseous lesions in the lung, together with arthritis, occurred in a bull on the same property. Nutritional and physical stress caused by a flood were thought to be predisposing factors. An unusually wet summer with prolonged flooding apparently provided suitable environmental conditions for saprophytic growth of Ps. pseudomallei in an area far south of the region in which infection of animals with this organism commonly occur.