Retrospective multicenter analysis of causes of death in wild mammals in Southern Germany (2019-2023).

Abstract

INTRODUCTION: Wild mammals are important indicators of ecosystem health, zoonotic risks, and anthropogenic pressures. Systematic necropsies provide valuable insights into mortality patterns, yet regionally structured evaluations in Central Europe remain scarce. METHODS: A total of 2,118 complete necropsy reports of wild mammals submitted to public veterinary investigation authorities in southern Germany between 2019 and 2023 were retrospectively analyzed. Data were categorized according to species, age, sex, season, and cause of death. Mortality causes were classified using the WHO ICD-11 system to enable standardized reporting and international comparability. RESULTS: The most frequently examined species were European hare, red fox, roe deerand wild boar. Infectious diseases were the leading cause of death, with tularemia and European brown hare syndrome predominantly affecting European hares, rabbit hemorrhagic disease occurring mainly in European rabbits and canine distemper virus representing the major infectious cause of death in red foxes, often showing distinct regional clustering. Trauma was the second most common cause of death, with road traffic collisions as the predominant factor. A pronounced seasonal mortality peak was observed in spring, particularly among adults. DISCUSSION: The present study highlights the multifactorial nature of wildlife mortality in southern Germany, with anthropogenic drivers playing a central role. It represents the first comprehensive regional overview of wildlife mortality in Germany based on complete necropsy datasets from all public veterinary investigation authorities in southern Germany. The ICD-11 classification proved useful for structuring mortality data and supports international comparability. These findings underline the value of necropsy-based surveillance as an important tool in One Health, informing conservation planning, wildlife management and public health risk assessment.