Canine filarial infections in an area of Central Italy (Tuscany-Latium border) historically free from the disease

This paper reports the presence of various species of filarial nematodes in dogs in an area of central Italy at the border between two regions (Tuscany-Latium), which had previously been free of infection and for which there are no epidemiological data in the literature. Blood and serum samples from a total of 363 adult dogs were collected during in 2016/17 and 2018/19 in the provinces of Grosseto (Tuscany) and Viterbo (Latium). The dogs were of different breeds or mixed breeds, randomly selected, and living in public kennels or privately owned. Of the 363 samples tested, 55 dogs were positive to Knott's test for microfilariae (prevalence 15.1%; 95% confidence interval: 11.5–18.8%). Dirofilaria immitis was found in 25 cases (prevalence 6.9%; 95% CI 4.3–9.5%), D. repens in 27 (7.4%, 95% CI 4.7–10.1%) and Acanthocheilonema reconditum in 3 (0.8%, 95% CI 0.1–1.7%). Out of 55 dogs, only four were infested with both D. immitis and D. repens (1.1%, 95% CI 0.001–2.2%).