Haemorrhagic septicaemia (HS) is one of the most common bacterial disease of buffaloes, cattle, sheep and goat. Buffaloes are more susceptible to it than are cattle. The causative organism (Pasteurella multocida) was isolated from clinically positive cases of hemorrhagic septicemia and identified from blood samples based on morphological characteristics. The organism with Gram’s staining method appeared Gram negative under oil immersion lens, as coccobacillary thin rods with rounded ends and non-spore forming cells. The size of the organism was variable with repeated subculturing but the shape remained almost consistent with a tendency to bipolar staining. The capsule of the organism was observed as delineated with India ink and bipolarity was observed as dumble shaped. The sugar fermentation was uniform for all the suspected isolates induced fermentation of glucose, sucrose, mannose and fructose with the production of acid only and no gas. Pathogenicity of P. multocida was confirmed in rabbits. It proved highly virulent to rabbits and they died within 24 hours. No death was recorded in control. The postmortem lesion observed included those of generalized septicemia like congestion of the internal organs, excessive hemorrhage particularly on laryngeotracheal region, accumulation of inflammatory fluid in the thoracic and peritoneal cavities.