Canine piroplasmosis in Italy: epidemiological aspects in vertebrate and invertebrate hosts

In Italy, canine piroplasmosis is believed to be widespread, but few data are available on its presence in most areas. In 2005 and 2006, vertebrate and invertebrate hosts were investigated in Central and Northern Regions of the Country. Microscopy on blood smears, molecular tools and serological tests were applied to 420 blood samples collected from dogs, in order to evaluate the presence of these protozoa and to identify possible risk factors. Moreover, ticks were analyzed by molecular techniques. Microscopy identified as positive 2.8% of the animals, all from Central Italy, and PCR detected 'piroplasm' DNA in 6.0%. Serology evidenced a mean prevalence of 34.0% with a decreasing trend from Central to Northern areas. The 507 collected ticks were identified as belonging to 8 species, mostly represented by Rhipicephalus sanguineus (n=376) and Ixodes ricinus (n=58). Molecular analyses evidenced the presence of babesial parasites (Babesia canis canis, B. canis vogeli, B. microti-like) in 25 (4.9%) of them; in Rh. sanguineus there was also demonstration of the vertical transmission of B. canis canis. Statistical analysis identified 'kennel' as risk factor for Babesia infection. Our findings evidenced that different species of piroplasms potentially infectious for dogs are circulating in Italy, and that epidemiological aspects of these infections are more complex than expected. Vector importance of both Rh. sanguineus and I. ricinus is hypothesized, but further investigation is needed.