Pathological findings in the red fox (Vulpes vulpes), stone marten (Martes foina) and raccoon dog (Nyctereutes procyonoides), with special emphasis on infectious and zoonotic agents in Northern Germany

Abstract

Anthropogenic landscape changes contributed to the reduction of availability of habitats to wild animals. Hence, the presence of wild terrestrial carnivores in urban and peri-urban sites has increased considerably over the years implying an increased risk of interspecies spillover of infectious diseases and the transmission of zoonoses. The present study provides a detailed characterisation of the health status of the red fox (Vulpes vulpes), stone marten (Martes foina) and raccoon dog (Nyctereutes procyonoides) in their natural rural and peri-urban habitats in Schleswig-Holstein, Germany between November 2013 and January 2016 with focus on zoonoses and infectious diseases that are potentially threatening to other wildlife or domestic animal species. 79 red foxes, 17 stone martens and 10 raccoon dogs were collected from traps or hunts. In order to detect morphological changes and potential infectious diseases, necropsy and pathohistological work-up was performed. Additionally, in selected animals immunohistochemistry (influenza A virus, parvovirus, feline leukemia virus, Borna disease virus, tick-borne encephalitis, canine adenovirus, Neospora caninum, Toxoplasma gondii and Listeria monocytogenes), next-generation sequencing, polymerase chain reaction (fox circovirus) and serum-neutralisation analysis (canine distemper virus) were performed. Furthermore, all animals were screened for fox rabies virus (immunofluorescence), canine distemper virus (immunohistochemistry) and Aujeszky’s disease (virus cultivation). The most important findings included encephalitis (n = 16) and pneumonia (n = 20). None of the investigations revealed a specific cause for the observed morphological alterations except for one animal with an elevated serum titer of 1:160 for canine distemper. Animals displayed macroscopically and/or histopathologically detectable infections with parasites, including Taenia sp., Toxocara sp. and Alaria alata. In summary, wildlife predators carry zoonotic parasitic disease and suffer from inflammatory diseases of yet unknown etiology, possibly bearing infectious potential for other animal species and humans. This study highlights the value of monitoring terrestrial wildlife following the “One Health” notion, to estimate the incidence and the possible spread of zoonotic pathogens and to avoid animal to animal spillover as well as transmission to humans.

Factors affecting the spread of parasites in populations of wild European terrestrial mammals

“…The ways in which humans acquire zoonotic parasites are complex. Definitive hosts for parasites such as Echinococcus multilocularis shed parasite eggs into the environment; this further leads to a persistent source of infection not only for intermediate hosts like rodents, but also for humans as incidental hosts (Bastien et al , 2002a Red fox, raccoon dog Red fox, wild boar Austria Duscher et al (2017) Raccoon dog, red fox, stoat, least weasel, river otter, wolf, polecat, American mink Belarus Pozio (2000); ; , 2001a, b, 2002a, b, 2003; Sutor et al Red fox, golden jackal Serbia Dmitric et al (2017) 2018; Karamon et al 2014;Lempp et al 2017). Some parasites settle in the muscle tissue of hosts, e.g., Alaria spp., Trichinella spp., Spirometra sp., and Toxoplasma spp.…”

Research into Neospora caninum—What Have We Learnt in the Last Thirty Years?

“…The 16 publications group into several topic areas; studies of the prevalence and risk factors for N. caninum infection for different species in different parts of the world, as varied as dogs [ 82 ], cats [ 83 ], cattle [ 84 ], small ruminants [ 85 , 86 , 87 ], horses [ 88 ] and wildlife [ 89 ].…”

Association of Batai Virus Infection and Encephalitis in Harbor Seals, Germany, 2016

“…Routine immunohistochemical tests of the seal brain for morbilliviruses, Borna disease virus, and tick-borne encephalitis virus ( 7 , 8 ) and immunofluorescence analysis for rabies virus were performed by the Department of Consumer and Food Safety of Lower Saxony (Hannover, Germany). All tests showed negative results.…”