Pathology of spontaneous tuberculosis and pseudotuberculosis in fish

Abstract

Abstract. The pathology of two infectious granulomatous diseases of aquarium‐maintained fish are described. Two fish showed widespread occurrences of hard and soft tubercles which contained clumps of acid‐fast bacilli, confirming the diagnosis of fish tuberculosis. Four other fish showed predominantly large soft tubercles containing peripheral arrangement of Gram‐negative, non‐acid fast bacilli diagnosed as flavobacterium. The various features are described and discussed with emphasis on differential diagnosis.