title: Health screening of free-ranging European brown hares (Lepus europaeus) on the German North-Sea island Pellworm.
abstract: BACKGROUND
  A sudden decline of the European brown hare (Lepus europaeus) population in one of the best hunting districts for small game species in northern Germany, the German North-Sea island Pellworm, in the years 2007/08 following marked habitat changes led to the implementation of a thorough health assessment program of the population. 110 animals were collected during the normal hunting season in the years 2010 and 2011. A post-mortem examination and histopathological investigation was performed on all animals. Additionally, routine bacteriology of the small intestine and parasitology were carried out. Sera of hares were tested for European Brown Hare Syndrome (EBHS) by enzyme linked immunosorbent assay, and for Treponema sp. by indirect immunofluorescent test. Additional testing was performed when deemed necessary.
  
  
  RESULTS
  The most striking result was a shift in the intestinal bacterial flora towards Gram-negative Enterobacteriaceae with a predominance of either Escherichia coli, or Aeromonas sp., or a high-grade double-infection with these two pathogens with subsequent catarrhal enteritis. Additionally, a marked coccidiosis, and varying infestations with the nematode Trichostrongylus retortaeformis were found. The sero-prevalence for EBHS was 78.1%, and for Treponema 43.9%.
  
  
  CONCLUSIONS
  The shift and decrease in diversity of the intestinal flora was the main and most consistent result found. In the authors' opinion the change of the habitat combined with other stressors increased the animals' sensitivity to ubiquitous bacterial species and parasites which usually would not have such fatal effects.
authors.affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria. Annika.Posautz@vetmeduni.ac.at.
authors.forename: Annika
authors.initials: A
authors.lastname: Posautz
authors.affiliation: Institute of Bacteriology, Mycology and Hygiene, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria. Igor.Loncaric@vetmeduni.ac.at.
authors.forename: Igor
authors.initials: I
authors.lastname: Loncaric
authors.affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria. marielundin_@hotmail.com.
authors.forename: Marie
authors.initials: M
authors.lastname: Lundin
authors.affiliation: Game Conservancy Deutschland e.V, Schloßstrasse 1, 86723, Oettingen, Germany. d.hoffmann@gameconservancy.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hoffmann
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Via Bianchi 7/9, 25124, Brescia, Italy. antonio.lavazza@izsler.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lavazza
authors.affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria. 1145140@students.vetmeduni.ac.at.
authors.forename: Zsofia
authors.initials: Z
authors.lastname: Kelemen
authors.affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria. Christoph.Beiglboeck@vetmeduni.ac.at.
authors.forename: Christoph
authors.initials: C
authors.lastname: Beiglböck
authors.affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria. Chris.Walzer@vetmeduni.ac.at.
authors.forename: Christian
authors.initials: C
authors.lastname: Walzer
authors.affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria. Anna.Kuebber@vetmeduni.ac.at.
authors.forename: Anna
authors.initials: A
authors.lastname: Kübber-Heiss
mesh_terms: D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary; D005858:Germany; D034621:Hares / Q000382:microbiology / Q000469:parasitology / Q000502:physiology*; D006304:Health Status; D062312:Islands; D011157:Population Dynamics