Molecular Diagnosis and Identification of Equine Piroplasms: Challenges and Insights from a Study in Northern Italy

Equine piroplasmosis is a tick-borne disease with significant health and economic impacts on the equine industry. Various piroplasm species and genotypes belonging to Babesia and Theileria genera have been identified as causative agents of this disease in horses, and recent studies highlight treatment differences depending on the species involved. Therefore, knowing which piroplasm species are circulating in a specific area is crucial, and highly sensitive diagnostic methods are needed to identify and differentiate the pathogen responsible for the infection. The aims of our study were to compare the diagnostic performance of different molecular tests for piroplasm DNA detection and genetically characterize the piroplasms identified in 63 horses in Northern Italy from 2016 to 2022. Molecular analysis revealed a 38.1% positivity rate within the tested population. Notably, substantial genetic variability was observed among the identified theileria rather than among the babesia. No single diagnostic method was found to reliably detect and differentiate all piroplasm species involved in equine piroplasmosis. This study highlights the need for further investigation into the genetic diversity of these parasites. Expanding our understanding of piroplasm variability is essential to develop and implement appropriate diagnostic methods for the accurate detection of equine piroplasmosis.