AUTHOR=Ciuca Lavinia , Caruso Valeria , Illiano Sergio , Bosco Antonio , Maurelli Maria Paola , Rinaldi Laura 

TITLE=Emerging risk of Dirofilaria spp. infection in shelter dogs in southern Italy

JOURNAL=Frontiers in Veterinary Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1112036

DOI=10.3389/fvets.2023.1112036

ISSN=2297-1769

ABSTRACT=<p>In southern Italy, the number of autochthonous cases of <italic>Dirofilaria immitis</italic> in dogs has increased considerably. This also occurs in the Campania region, particularly in coastal areas, where infections with <italic>D. immitis</italic> and <italic>Dirofilaria repens</italic> have been reported more frequently. Therefore the aim of the present study was to better investigate the occurrence of <italic>Dirofilaria</italic> spp. in a local dog shelter in Castel Volturno (Campania region, southern Italy). Briefly, a total of 260 blood samples were analysed for identification of microfilariae (mff) and detection of <italic>Dirofilaria immitis</italic> antigen. Dogs were classified according to their age (1–3  years; 4–6  years; 7–11  years; &gt; 11  years) and length of stay in the shelter at the time of sampling (dogs that entered in the shelter in the last 4  months; dogs housed in the shelter for more than 4 months up to 2  years; dogs housed for more than 2  years). The modified Knott’s test revealed that 195 dogs (75.0%) were positive for circulating mff of <italic>Dirofilaria</italic> spp. Specifically, 104/260 (40.0%) dogs were positive for <italic>D. immitis</italic> and 91/260 (35.0%) were positive for <italic>D. repens</italic>. In addition, 72/260 (27.7%) dogs had both <italic>D. immitis</italic> and <italic>D. repens</italic> mff. Antigen testing revealed that 78/260 (30.0%) dogs were positive for <italic>D. immitis</italic>. However, 26/104 (25.0%) of the dogs with <italic>D. immitis</italic> mff were antigen-negative. The overall k concordance between the modified Knott’s test and the antigenic test was ≤0.2 (poor) (<italic>p</italic> = 0.000). The results of the logistic regression model showed a significant association between <italic>Dirofilaria</italic> exposure and the period of time the dogs had spent in the shelter at the time of sampling. Dogs housed in the shelter for 4 months (group 1) and between 4 months and 2 years (group 2) had higher <italic>Dirofilaria</italic> positivity than dogs in group 3 (housed for more than 2 years) (80.4% vs. 79.6% vs. 62.4%, respectively). Moreover, male dogs and older dogs (between 7 and 11 years of age) were more likely to be infected with <italic>Dirofilaria</italic> spp.</p>