Abstract

Hunters in Schleswig-Holstein, Germany have observed a decrease of European brown hares (Lepus europaeus) associated with an increasing number of diseased animals. In 2017, 111 post-mortem examinations on 60 hunted and 51 deceased hares were performed. From each hunting ground, 20 animals were chosen randomly and blood samples were taken immediately after death. During necropsies, samples were collected for histopathology, microbiology and parasitology. Additionally, we screened for European brown hare syndrome virus (EBHSV), rabbit haemorrhagic disease virus type 2 (RHDV-2) and Francisella tularensis (tularaemia).

Liver tissues were negative for tularaemia, EBHSV and RHDV-2. No antibodies for Francisella tularensis were found (n=57). Histopathological results included findings such as lympho-histiocytic hepatitis, hyperplasia of mesenteric lymph nodes and spleen, lympho-plasmacellular or granulomatous enteritis, granulomatous-necrotizing steatitis as well as interstitial nephritis. The parasitological analyses (n=107) demonstrated marked intestinal coccidiosis in almost all cases (99%). Additionally, gastrointestinal strongylids (65%) and Trichuris spp. (8%) occurred in some individuals. Yersinia enterocolitica (n=4) and pseudotuberculosis (n=2), Salmonella sp. (n=1), Pasteurella multocida (n=1) and Staphylococcus aureus (n=4) were detected in different tissue. In two hares antigen analyses (culture) for Brucella sp. were positive. Furthermore, Escherichia coli was detected in many hares. This project contributes to the advancement in preventive protection of public health and food safety. A higher sample size is needed to verify our results. In future investigations non-infectious noxae should be included to elucidate the causes of the hunting bag decline of European brown hares in Schleswig-Holstein.