Abstract

Topic: Physiology, diseases and genetics

Survey of pathogens associated with the respiratory system of moose (Alces alces) population in Poland.

Katarzyna Filip-Hutsch¹, Ewelina Kwiecień², Katarzyna Kliczkowska³, Anna Rodo³, Anna Didkowska⁴, Tomasz Hutsch³, Magdalena Rzewuska², Krzysztof Anusz⁴, Anna M. Pyziel⁴

Department of Food Hygiene and Public Health Protection, Institute of Veterinary Medicine, Warsaw, Poland
Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
Department of Pathology and Veterinary Diagnostics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
Department of Food Hygiene and Public Health Protection, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland

The population of moose in Poland is estimated at 30,000 individuals and represents one of the largest groups of moose in central Europe. The western border of the European range of moose and the southernmost area of its distribution runs through Poland, making the population crucial for moose conservation. Global warming and increasing populations of other wildlife species might be the reason for the transmission of pathogens that are dangerous to moose health. One of the most important are those associated with respiratory diseases, as lungs are constantly exposed to numerous agents from the environment. The present study aimed to identify pathogens associated with the respiratory system of moose and describe histopathological changes observed in the lungs of animals. Lungs were collected during field dissections of 33 moose killed in road accidents or found dead in the years 2017 – 2025 in Poland. Samples of the lungs were preserved in 10% formalin for histopathological analysis. Lungs were also subjected to microbiological examination and cultured on Columbia Agar at 37 °C in an aerobic and 5% CO2 atmosphere. The trachea, bronchi, and bronchioles were cut open during parasitological examination. Nematodes were isolated from the lumen of the respiratory tract, preserved in 70% ethanol, and identified by amplification of partial SSU, cox1 and cytB. Lung fluid has been collected and frozen for further serological examination using commercial ELISA kits for antibodies against Mycoplasma spp., BVDV, BHV-1, and BTV. Most examined moose (21/33) showed macroscopic lung changes, including edema, congestion and features of pneumonia. Staphylococcus aureus was the most common bacterial species, followed by Escherichia coli and Enterobacter spp. Nematodes Dictyocaulus cervi were isolated from five individuals, and one moose was infected with the newly described species Dictyocaulus skrjabini. No antibodies against examined viral and bacterial agents were detected during the serological examination. Histopathological examination allowed the identification of emphysema, pulmonary fibrosis, mononuclear cell infiltration with interstitial inflammation or bronchopneumonia. Pathological changes in the respiratory system are commonly observed in moose in Poland. Therefore, the occurrence and spread of pathogens associated with lungs in the population of moose should be carefully monitored.