Microscopic and Genetic Detection of Hepatozoon spp. in Leopard Cats (Prionailurus bengalensis) and Raccoon Dogs (Nyctereutes procyonoides koreensis) from the Republic of Korea

Hepatozoon spp. are apicomplexan parasites with a heteroxenous life cycle involving vertebrate intermediate hosts and hematophagous arthropod definitive hosts. This study aimed to detect and characterize Hepatozoon spp. infections in two mesocarnivores, the endangered leopard cat (Prionailurus bengalensis) and the raccoon dog (Nyctereutes procyonoides koreensis), from the Republic of Korea using microscopy and PCR. Examination of peripheral blood samples from three leopard cats and 11 raccoon dogs by PCR detected Hepatozoon spp. DNA in three leopard cats and two raccoon dogs. Gamonts were visualized in blood smears from one leopard cat (of two examined) and one raccoon dog. Morphologically, Hepatozoon felis gamonts were predominantly centrally located within neutrophils, while Hepatozoon canis gamonts displaced the host nucleus to the periphery. Phylogenetic analysis of partial 18S rRNA gene sequences confirmed the presence of H. felis in leopard cats and H. canis in raccoon dogs, with isolates clustering alongside international sequences, suggesting low host specificity for H. canis and potential genetic diversity within H. felis. These findings expand knowledge about Hepatozoon spp. host associations in the Republic of Korea, highlighting the need for further epidemiological and pathological studies that particularly consider conservation concerns for leopard cats. Our results also emphasize the value of combining molecular and microscopic methods for a comprehensive assessment of hemoprotozoan infections in wildlife.