Long-term surveillance of Dirofilaria immitis in wild carnivores from Serbia (2013–2025)

Introduction: Dirofilaria immitis is a parasitic nematode primarily affecting domestic dogs but also found in wild carnivores. This study builds on previous findings 1, to further assess the prevalence of D. immitis in wild carnivores in Serbia and explore potential transmission risks to domestic dogs. Methods: A total of 962 wild carnivore hearts were obtained in collaboration with hunters or as a roadkill. The hearts were macroscopically examined, and the Dirofilaria immitis specimens from the positive hosts were stored in ethanol for further analysis. Results: During the research period from 2013 to 2025, total of 82 wild animals were positive for D. immitis. Infected species included 76 golden jackals (Canis aureus), 1 wolf (Canis lupus), 1 otter (Lutra lutra), and 4 red foxes (Vulpes vulpes). No infection was found in beavers, wild cats, beech martens, pine martens, badgers, weasels, or brown bears. A higher prevalence in golden jackals was observed, likely due to their habitat preferences in areas of lower altitudes, and riverine regions where mosquito vectors are abundant. Conclusions: The high prevalence of D. immitis in golden jackals suggests that they may represent an important reservoir for the parasite, especially in Serbia, where jackals have preference toward anthropogenically modified habitats. These habitats, which are often located in lower altitudes, and riverine areas, likely provide an abundance of mosquito vectors that facilitate the transmission of D. immitis. This finding highlights the increased risk of transmission to domestic dogs, particularly in regions with high jackal populations, and emphasises the need to monitor D. immitis in both wildlife and domestic dogs to prevent zoonotic transmission.