Seroepidemiological study of Leishmania infantum, Toxoplasma gondii and Dirofilaria immitis in pet ferrets (Mustela putorius furo) in Spain

Ferrets are susceptible to infections with Leishmania infantum, Toxoplasma gondii, and Dirofilaria immitis; however, epidemiological data on these infections are limited in Europe. A total of 448 serum samples from household ferrets were collected between December 2019 and December 2023 in Spain. In this study, we assessed the seroprevalence of L. infantum and D. immitis using an in-house enzyme-linked immunosorbent assay (ELISA) and T. gondii using an in-house immunofluorescence antibody test (IFAT). Among the ferrets tested, the seroprevalence was 10.49% (47/448) for L. infantum, 2.68% (12/448) for T. gondii and 10.27% (46/448) for D. immitis. There was no significant association between seropositivity and age, gender, neutering status, cohabitation, lifestyle, and collection date. Ferrets classified as sick animals related to the presence of compatible or non-compatible signs showed a higher seropositivity rate for L. infantum (15.90%) compared to subclinical animals (4.76%). Overall, 23.44% (105/448) of the samples were seropositive for at least one of the three parasitic agents, 3.12% (15/448) were positive for two agents, and 0.22% (1/448) tested positive for all three agents. Co-infections were also evaluated, revealing that 12.76% (6/47) of L. infantum seropositive ferrets were also positive for T. gondii (p = 0.011) and 21.27% (10/47) for D. immitis (p = 0.009). To the best of our knowledge, this is the first report on the seroprevalence of L. infantum, D. immitis, and T. gondii within the ferret population in Spain. Understanding the epidemiological status of these and other zoonotic pathogens is crucial for enhancing surveillance in both veterinary and public health sectors, as well as for strengthening prevention and control strategies.