Canine Vector-Borne Diseases (CVBDs) in Liguria, North-West Italy: A Retrospective Study over an 11-Year Period (2013–2023).

Simple Summary: Dogs can be affected by diseases transmitted by arthropod vectors, some of which can also be transmitted to humans. The aim of this study was to present the results of diagnostic tests for selected pathogens (Anaplasma spp., Ehrlichia spp., Borrelia burgdorferi sensu lato (s.l.), Rickettsia conorii, and Dirofilaria immitis) conducted by a public veterinary diagnostic laboratory (Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, IZSPLV) in Liguria, north-west Italy, over an 11-year period (2013–2023). Overall, 18.8% of the dogs tested positive for at least one pathogen. In detail, most positive dogs showed exposure to R. conorii, followed by Anaplasma spp., Ehrlichia sp., D. immitis, and B. burgdorferi s.l. This work contributes to the description of the epidemiology of the selected pathogens in Liguria, showing a widespread exposure of dogs to Rickettsia spp., while the other pathogens appear to be less frequent compared to other areas of Italy. Canine vector-borne diseases (CVBDs) pose a global threat to both canine and public health. This study evaluates the prevalence of Anaplasma spp., Ehrlichia spp., Borrelia burgdorferi sensu lato (s.l.), Rickettsia conorii, and Dirofilaria immitis in domestic dogs in Liguria, north-west Italy, a region where data were lacking. From 2013 to 2023, 8584 blood samples from shelter (74%) and owned dogs (26%) were submitted to the Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta (IZSPLV) for serological testing (indirect immunofluorescence and/or rapid immunochromatographic tests). Overall, 18.8% (95% CI: 18.0–19.7) of the dogs tested positive for at least one pathogen, with positivity against R. conorii antigen being the most frequently recorded (24.4%, 95% CI: 23.3–25.5). Lower prevalence levels were observed for Anaplasma spp. (1.82%, 95% CI: 1.47–2.23), Ehrlichia spp., (1.25%, 95% CI: 0.97–1.60), B. burgdorferi s.l. (0.22%, 95% CI: 0.11–0.39), and D. immitis (0.84%, 95% CI: 0.65–1.06). Positive cases for all pathogens increased over time, with prevalence differing significantly between owned and shelter dogs. Topographical factors, land use, and monthly relative humidity appeared to influence the positivity in the dogs. These results update the epidemiology of the investigated CVBDs in Liguria, indicating a widespread exposure to Rickettsia spp. among local dogs. [ABSTRACT FROM AUTHOR]