Occurrence of Dirofilaria immitis (Nematoda, Onchocercidae) in Red Foxes (Vulpes vulpes) from the Suburbs of Kharkiv (Ukraine)

Abstract

Dirofilariasis of animals and humans is a disease caused by nematodes of the genus Dirofilaria (Railliet et Henry, 1911). The role of wild predators, particularly the red fox (Vulpes vulpes) (Linnaeus, 1758) in the distribution of pathogen of the genus Dirofilaria in the world remains unclear. We studied the occurrence of Dirofilaria immitis (Leidy, 1856) in a population of the red fox. Twenty-seven foxes were examined during the winter hunting season of 2019–2020 in Dergachi district, Kharkiv region of Ukraine. All 27 examined foxes were older than 1.5–2 years old, 5 of them (18.5 %) were 4–5 years old. Dirofilaria immitis was found in 22.2 % of foxes. The intensity of infection ranged from 2 to 4 specimens of nematodes per host. In four foxes (66.7 % of infected hosts), the same number of male and female nematodes was detected, while two foxes (33.3 %) had each 1 male and 2 females of D. immitis. The length of D. immitis males (7 specimens) was 13.96 ± 0.29 cm and the length of females (9 specimens) was 19.58 ± 0.55 cm. Prevalence of infection of foxes with D. immitis presumably depends on their habitat and the presence of mosquitos (vectors of the nematode) in these areas.