Pathomorphological, bacteriological and virological features of pneumonia in captive monkeys

Introduction. Respiratory infections pose a significant challenge in veterinary practice due to their high prevalence across various animal species. Pneumonia and gastrointestinal diseases are leading causes of mortality in captive primates. Objective. Study of pneumonia incidence in monkeys, the analysis of pulmonary microbiota composition, study of pathomorphological lesions in lung tissue. Materials and methods. Common methods were used for pathomorphological, microscopic and bacteriological examinations of 1,862 dead monkeys. Lung samples and serum samples from 126 monkeys died of pneumonia in 2021–2024 were tested for acute respiratory viral pathogens as well as for antibodies to them with polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Results. Pneumonia was postmortem diagnosed in 865 monkeys (46.5%). The mortality rate for pneumonia in baby monkeys during their first month of life reached 100%. In baby monkeys under one year of age, the mortality rate was 65.4%. The obtained data showed that the disease incidence in these age groups was high. Deaths of monkeys due to pneumonia were reported throughout the year. Based on postmortem examinations, bilateral polysegmental bronchopneumonia was the most frequent finding, lobar fibrinous pneumonia affecting the right lung was less common. Microscopic analysis detected purulent exudate and cocci bacteria in the bronchial lumen. The predominant bacteria isolated from lung tissue were enterobacteria (58.5%) and Gram-positive cocci (36.6%). Various microorganisms were isolated but the most frequently enteric bacteria were as follows: Escherichia coli (66.1%), Enterococcus spp. (27.5%) and Proteus spp. (31.5%). The following bacterial pathogens associated with pneumonia were detected: Staphylococcus aureus (31.5%), Klebsiella pneumoniae (2.2%), Pseudomonas aeruginosa (0.8%) and Streptococcus pneumoniae (0.6%). Adenoviruses, human parainfluenza viruses of type 1 and type 3 and respiratory syncytial virus (RSV) were also circulated in the monkey colony. Conclusion. During analysis of microbial etiology of pneumonia in monkeys it shall be considered that pneumonia is frequently arisen as a secondary infection, heavily influenced by underlying gastrointestinal pathologies and immunosuppression.