Causes of Death and Screening for Toxicants and Hemopathogens of European Hedgehogs (Erinaceus europaeus) from a Wildlife Rehabilitation Center in Northern France

Abstract

The European hedgehog (Erinaceus europaeus), common in rural and suburban environments, is perceived as declining within its native range, prompting conservation concerns. This study of hedgehogs admitted to a French rehabilitation center aimed to identify causes of death, detect potential emerging diseases, and systematically screen dead hedgehogs for toxicants and hemopathogens. Using clinical information, necropsy examination, and ancillary testing in 159 dead hedgehogs, we identified the primary cause of death of 92% of them. The leading causes of death were impaired general condition (30%); bacterial infections (26%), frequently caused by Salmonella Enteritidis; and trauma (20%). Additional factors contributing to death were identified in 78%, including a high proportion with significant parasite infestations. Toxicologic screening revealed that 42% of hedgehogs had been exposed to anticoagulant rodenticides, including 6.4% hedgehogs with levels compatible with acute intoxication. These hedgehogs were also exposed to trace metals, especially lead, but no pesticides residues were detected. Hemopathogen screening revealed a low diversity and prevalence of blood pathogens with 3.6, 2.9, and 2.9% individuals infected with Anaplasma phagocytophilum, Mycoplasma turicensis, and Mycoplasma wenyonii, respectively. The variety of diagnoses suggests that there is no unique prominent or emerging disease responsible for the mortality of these hedgehogs. This study also highlighted the high exposure of hedgehogs to various toxicants. To further investigate the extent and causes of population declines, health information issued from several centers should be combined with demographic data as well as ecologic assessments on the availability and quality of natural resources.

Keywords: Salmonella Enteritidis; Anticoagulant rodenticides; diseases; gross pathology; histopathology; intoxication; necropsy; parasites; toxicology.