In the experiment on the study of the differential diagnosis of mixed bacterial infections in birds, 16 chickens of 40 days of age were used. Chickens were divided into two groups: experimental (10 heads) and control 6 heads. Experimental
chickens were infected with daily cultures of E. coli, Pasterella multocida. As a result of the studies of experimental chickens, pronounced clinical signs and pathomorphological changes in the internal parenchymal organs, characteristic of both pasteurellosis and escherichiosis.