Status of Infectious Diseases in Free-Ranging European Brown Hares (Lepus europaeus) Found Dead between 2017 and 2020 in Schleswig-Holstein, Germany

[Zoonoses in endemic, free-ranging mammals]

BACKGROUND

Zoonoses are diseases and infections that can be transmitted naturally between animals and humans. Direct and indirect contact of humans with wildlife occur during hunting activities, when diseased wildlife is found and treated, and in shared fields, forests, parks, gardens, and homes. Zoonoses can only be understood and controlled when ecosystems, animals, and humans are considered holistically.

OBJECTIVE

This paper presents important zoonotic pathogens that are currently present in wild mammals as reservoirs in Germany.

MATERIAL AND METHODS

The literature was searched to determine the prevalence of zoonotic pathogens currently occurring in wild mammals.

RESULTS

Viral zoonotic agents currently present in free-ranging, mammalian animals in Germany as reservoirs of natural origin are bornaviruses, lyssaviruses, hepatitis E virus genotype 3, and Puumala orthohantavirus. Bacterial zoonotic agents beyond typical wound and foodborne pathogens include Brucella suis Biovar 2, Francisella tularensis ssp. holarctica, Leptospira interrogans sensu latu, Mycobacterium caprae, and Yersinia pseudotuberculosis. In particular, parasitic zoonotic agents common in wildlife are Alaria alata, Baylisascaris procyonis, Echinococcus multilocularis, Sacoptes scabei, and Trichinella spp.

CONCLUSION

The presence of zoonotic infectious agents of risk groups 2 and 3 has to be regularly expected in numerous endemic wildlife species, especially canines, small bears, rodents, insectivores, and bats. Animal caretakers, hunters, veterinarians, and human health professionals should be aware of this risk and take protective measures appropriate to the situation.

Influence of age, habitat elevation, and distance to a thermal power plant on pathomorphological findings in the European brown hare (Lepuseuropaeus P.)

The lifespan of the European hare (Lepus europaeus P.) is affected by a number of negative factors, including pollutants. In this paper, the individual and joint influence of age and habitat (elevation and distance from the thermal power plant - TPP) on pathomorphological findings of hares shot during three hunting seasons was investigated. Pathomorphological changes were found in 95.12% of hares. In hares up to 1 year of age, the changes were predominant in the lungs, and in older hares, in the kidneys. Degenerative changes in kidneys and liver and inflammatory changes in kidneys and lungs were considered important most in discussing the influence of chemical pollution. The proximity of TPP influenced the type of changes in the liver. A significant joint effect of age and elevation on the type of changes in the lungs of adult hares and on the heart of young hares was found. Elevation and distance from TPP had a joint effect on the occurrence of changes in the lungs, intestines, and heart in hares from the field farther from TPP. The results indicate that the hares were highly exposed to chemical pollutants that may affect their immunity, and lifespan.

Malicious Mites-Sarcoptes scabiei in Raccoon Dogs (Nyctereutes procyonoides) in Schleswig-Holstein, Germany

Sarcoptic mange was detected in five free-ranging raccoon dogs (Nyctereutes procyonoides) in the federal state of Schleswig-Holstein, Germany, during a health assessment study of invasive species, including raccoon dogs, carried out between 2021 and 2022. Four raccoon dogs showed severe lesions, including extensive alopecia with thickening and hyperpigmentation of the skin (lichenification). The fifth animal was less affected, showing only thinning of the hair coat in multiple body locations. Skin scrapings were performed and confirmed the presence of Sarcoptes scabiei. Histopathology of the skin revealed diffuse epidermal hyperplasia and hyperkeratosis, mild eosinophilic dermatitis, and varying amounts of intralesional mites. Staphylococcus pseudintermedius and Corynebacterium auriscanis were detected in the skin samples of the affected animals, indicating a secondary bacterial infection. The source of sarcoptic mange remains unclear; interspecies transmission via direct or indirect contact seems likely. Raccoon dogs are therefore a potential vector for sarcoptic mange, and their behaviour could contribute to disease spread and persistence.

Pathomorphological Findings and Infectious Diseases in Selected European Brown Hare (Lepus europaeus Pallas, 1778) Populations from Schleswig-Holstein, Germany

In the northernmost German federal state Schleswig-Holstein, populations of European brown hares (Lepus europaeus Pallas, 1778) show diverse densities and varying courses over the years. To examine differences in pathomorphological findings and infectious diseases as possible reasons for varying population dynamics, we assessed 155 hunted hares from three locations in Schleswig-Holstein from 2016 to 2020. We investigated the association of location, year, age, and sex of animals to certain pathomorphological findings and infectious diseases. Frequent pathomorphological findings were intestinal parasites (63.9%), hepatitis (55.5%), nephritis (31.0%), steatitis (23.2%), enteritis (13.5%), and pneumonia (5.2%). Body condition differed significantly between locations, and the prevalence of pneumonia was significantly higher in females. Enteritis was not detected in 2019, when much more juveniles were sampled. Hepatitis and nephritis occurred significantly more often in 2016 and among adults. Additionally, more adults showed hepatitis with concurrent serotitre for European brown hare syndrome virus (EBHSV), while intestinal parasitosis as well as high excretion rates of coccidia were more common in juveniles. Sampled animals showed high infection rates with Eimeria spp. (96.1%), Trichostrongylus spp. (52.0%), Graphidium strigosum (41.2%), and a high seroprevalence (90.9%) for EBHSV, without severe symptoms. This study revealed a low prevalence of infectious pathogens, but a high prevalence of chronic inflammations of unknown origin in the tested brown hare populations. Overall, our results indicate a rather minor importance of infectious diseases for observed population dynamics of analysed hare populations in Schleswig-Holstein.