Pathological changes in mixed bacterial infections of birds

The article presents data on pathological changes in the body of birds experimentally infected with pathogens of colibacteriosis, pullorosis and pasteurellosis of birds. Experiments have shown that when chickens are infected with 2–3 species of pathogens, the mentioned infections occur with severe clinical signs and complex pathological changes. At the same time, transience, high mortality with a severe form of the disease were clarified. More pronounced pathological changes were observed with a prolonged (5–6 days) course of the disease. In the acute course of this mixed infection, the liver is enlarged with small areas of necrosis, signs of acute catarrhal enteritis are observed. A higher pathogenicity of the pathogen of pasteurellosis P.multocida was found in the associated course with pullorosis and colibacteriosis, in contrast to mono infections. In this case, the pathogen P.multocida, in combination with S. pullorum-gallinarum and E. coli, was more aggressive and therefore the infection process was more difficult as a synergy.