Abstract
Pasteurellosis caused by Pasteurella multocida is one of the most widespread and dangerous infectious diseases of cattle in the Republic of Kazakhstan, leading to significant economic losses due to high morbidity and mortality rates. The aim of the present study was to assess the epizootic situation of pasteurellosis in cattle farms of the Abai region, as well as to determine the etiological role of P. multocida and associated microflora in the development of the disease. The study was conducted using pathological material obtained from 43 clinically ill and deceased animals. Tissue samples of the liver, lungs, spleen, heart, and kidneys were used as the study objects. These samples were examined using bacteriological, microscopic, and biological methods. Microorganisms were identified based on their morphological, cultural, tinctorial, and biological characteristics in accordance with generally accepted protocols of veterinary microbiology. Pasteurella multocida was isolated from all examined organs in 100% of cases, confirming its leading etiological role. Opportunistic microorganisms (Escherichia coli, Staphylococcus aureus, and Streptococcus spp.) were detected less frequently and were predominantly found in mixed infections, primarily in lung, liver, and heart tissues. The results of microscopic and cultural analyses indicated a systemic nature of the infectious process. The data obtained indicate that bovine pasteurellosis in the Abai region is characterized by a generalized course, with P. multocida playing a dominant role, and the disease is often complicated by associated bacterial microflora. Comprehensive laboratory diagnostics is an essential measure in cattle-breeding farms for the timely detection and effective control of pasteurellosis.