Molecular Detection and Genetic Variability of Hepatozoon canis in Golden Jackals (Canis aureus L. 1758) in Serbia

In addition to infecting domestic dogs, Hepatozoon canis affects a large number of wild canids, such as foxes, jackals, and wolves, that can serve as reservoirs for this pathogen. In this study, we focused on the prevalence of H. canis, its genetic diversity, and its distribution in golden jackals on the territory of Serbia. At the same time, this is the first study in which a high genetic diversity of four sequence types (S4-S7) of H. canis has been found in golden jackals. In addition, a high prevalence rate was found, with 78.95% of animals testing positive for H. canis. Genetic analysis revealed variability at four positions, resulting in four different sequence types in golden jackals. Animals can become infected through the ingestion of infected ticks or by consuming infected prey, as well as transplacentally, from mother to offspring; what it could testify to 6/15 positive juvenile jackals. Additional research is crucial for elucidating transmission mechanisms, pinpointing potential sources of infection, and comprehending the ramifications of this pathogen for wild carnivores. Hepatozoon canis is a protozoan tick-borne parasite infecting domestic and wild canids, including foxes, wolves, and jackals. It is mainly found in dogs but has also been detected in several wild carnivores, including foxes, wolves, and jackals. Host transmission primarily occurs through the ingestion of infected ticks, typically Rhipicephalus sanguineus, with documented instances of transplacental transmission from infected females to cubs. In Serbia, the golden jackal is common throughout the country, and its population has increased in recent years. Previous research has documented the presence of several vector-borne pathogens in the jackal population in Serbia, so we conducted this study to determine the presence, prevalence, and genetic variability of H. canis. Over eleven years (2010-2020), 114 animal samples were collected from 23 localities in Serbia. A total of 90/114 (78.95%) jackals were positive for H. canis, and they came from 22 localities. Among 15 juveniles, almost half (6/15 (40%)) tested positive for H. canis. In addition to the high prevalence, high genetic variability of the pathogen was also found. According to the mutated positions, four sequence types (S4-S7) of H. canis were determined. Based on our earlier research on the grey wolf and on this study, it can be observed that various sequence types of H. canis circulate within wild canid populations in Serbia. The prevalence of H. canis infection in wild carnivores raises significant concerns for wildlife conservation and animal health. Infected animals may act as reservoirs for the disease, posing a potential risk to domestic animals by acting as a source of infection.