Molecular Identification, Occurrence, and Risk Factors for Small Babesia Species Among American Stafford Terriers in Serbia

In Serbia, <i>Babesia canis</i> is the predominant cause of canine babesiosis, while <i>B. gibsoni</i> and <i>B. vulpes</i> have been reported only sporadically. Limited awareness of these small Babesia species often leads to misdiagnosis and inappropriate treatment. International reports indicate that American Staffordshire Terriers (ASTs) and related breeds are particularly affected. This study examined 101 ASTs over a two-year period to determine the occurrence of small <i>Babesia</i> species and identify dog- and owner-related risk factors. Collected data included age, sex, body condition score (BCS), clinical signs, presence of scars, history of vector-borne diseases (VBD), living conditions, antiparasitic prophylaxis, and tick exposure. Molecular identification using PCR and Sanger sequencing revealed that 37 dogs were positive for <i>Babesia</i> spp.; among them, 36 were infected with <i>B. gibsoni</i> and one with <i>B. vulpes</i>. Significant risk factors associated with infection included the presence of scars, low BCS, history of VBDs, tick exposure, and living in rural areas. These findings demonstrate a notably high occurrence of <i>B. gibsoni</i> and the presence of <i>B. vulpes</i> in ASTs in Serbia. The results highlight the need for improved awareness, accurate molecular diagnostics, and targeted preventive and therapeutic measures. Additionally, observed risk factors suggest chronic infection and support transmission pathways linked to dog bites and tick exposure.