Babesia vulpes and Babesia banethi infections in red foxes: molecular and morphological detection with clinical and cytological findings

Red foxes are widespread carnivorans acting as reservoirs of Babesia vulpes, which is highly prevalent in foxes, yet its clinical impact remains poorly understood. The description of Babesia banethi raised knowledge gaps regarding pathogenicity and life cycle. This study investigated the occurrence of Babesia spp. in red foxes from southern Italy. Overall, 54 red foxes were clinically examined, sampled for hemato-biochemical analyses, and screened for Babesia spp. using microscopy and PCR. Necropsies were performed on 20 animals. Ticks were collected, identified, and dissected for cytological detection of Babesia spp., as well as by PCR. Overall, 46.3 % of foxes tested positive for Babesia spp., with B. vulpes (42.6 %) predominating and B. banethi detected in two animals. Blood smear concordance with PCR was high, and morphometric differences between B. vulpes and B. banethi were evident. Most infected foxes were young and had clinico-pathological alterations, although trauma-related comorbidities limited interpretation. Two B. banethi–positive foxes had clinical babesiosis, suggesting pathogenic potential. In necropsied foxes, Babesia DNA was most frequently detected in the brain and merozoites were observed in cerebral capillaries. Of 67 ticks collected, five species were identified, including Ixodes kaiseri, firstly reported in Italy. No Babesia stages were observed in tick organs, but B. banethi DNA was detected in one I. kaiseri. This study documents a high rate of B. vulpes infection and the sympatric presence of B. banethi in southern Italy. It represents the first clinico-epidemiological, hematological, cytological and molecular examination of Babesia spp. in live foxes. The detection of B. vulpes in brain enhances our understanding of parasite tropism, while the presence of B. banethi in I. kaiseri raises questions about transmission routes. These findings highlight the importance of surveilling fox populations and ticks, given the increasing reports of B. vulpes infection in dogs and the potential spillover at the wildlife–domestic interface.