Double Trouble: Co-Infection of Angyostrongylus Vasorum and Dirofilaria Immitis in the Golden Jackal (Canis Aureus Moeoticus) in Friuli Venezia Giulia, Italy

INTRODUCTION: In Italy, the golden jackal (Canis aureus) was confirmed as early as 1985, with numerous stable meta-populations currently established in Friuli venezia Giulia (FvG), making the development of a regional health monitoring and surveillance network necessary. while co-infection by cardiopulmonary nematodes Dirofilaria immitis and Angyostrongylus vasorum in golden jackal was previously reported in Europe (Gavrilović et al., 2017. Acta Parasitol, 62:880-84), their role as sylvatic hosts in Italy remains unreported and unclear. In this study, we report the first case of co-infection with A. vasorum and D. immitis identified in golden jackals from Friuli venezia Giulia, Italy, describing parasitological and anatomo-pathological findings and discussing epidemiological implications. MATERIALS AND METHODS: Data regarding golden jackal corpses retrieved in FvG were recorded in the InfoFaunaFvG regional wildlife surveillance network. From 2020 to date, 109 carcasses underwent necropsy at University of Udine, jointly with the IzSve and MFSN (Udine), to ascertain the death causes and for anatomopathological and parasitological exams. Of 109 animals, 57 were deemed suitable for cardiopulmonary parasitological examinations using a total worm count approach. Parasites were morphologically identified and then DNA extraction, amplification, and sequencing were performed for confirmation of species identity. RESULTS AND CONCLUSIONS: Road-killed jackals consistently showed fractures of appendicular skeleton, haemorrhagic abdominal and thoracic effusions. Prevalence of A. vasorum and D. immitis was 29.8% (95%CI: 18.8-43.6%) and 7% (95%CI: 2.3-17.8%) respectively, and mean intensity was 6 (range 1-56) and 4 (range 3-6). D. immitis adults were mainly located in the heart and, in one case, both in the heart and pulmonary arteries. In the last two years, 3 out of 57 animals (5.3%, 95%CI: 1.8- 14.4) were found co-infected with both A. vasorum and D. immitis. Histologically, the lung parenchyma was multifocally effaced by clusters of granulomas, containing small central deposits of necrotic tissue and occasionally small, calcified areas. Primitive and embryonated nematode eggs and larvae were embedded within the inflammatory foci. The alveolar septa were thickened by lymphohistiocytic infiltration. In addition, adult nematodes were found in blood vessels concurrently with thrombotic lesions. To the best of the authors’ knowledge, this is the first report of A. vasorum and D. immitis co-infection in golden jackals in Italy (second in Europe). wild carnivores such as this species are recognized hosts of D. immitis and A. vasorum, indicating the existence of their sylvatic cycle. Similarly to dogs, golden jackals are susceptible to potentially fatal cardiovascular and pulmonary complications due to these nematodes. Their adaptability and potential presence in urban contexts raise concern for increased parasite transmission, especially to non-endemic regions.