Abstract
A case of peritonitis caused by Actinomycotic spp is reported in a 12-year-old male Siberian tiger. Grossly, the mesentery was markedly thickened and contained numerous 1 to 3 mm diameter, white to yellowish foci. Fibrous adhesion showing tumorous thickening was also noted between the mesentery and abdominal organs. Histologicallyi the thickened mesentery and masses consisted of necrotic center with bacterial colonies surrounded by eosinophilic club (Splendore-hoeppli), neutrophils, macrophages, a few Iymphocytes and fibrosis. The bacterial colonies stained positvely with Gram's stain but were negative on acid-fast and periodic acid-Schifr method. Howeverr since the bacterial culture was not availablei the definitive causative agent was not able to specified.
