A nationwide epidemiological update on respiratory and intestinal nematodes in at-risk dogs in Italy

This study updates current information on the occurrence of Capillaria aerophila, Capillaria boehmi and Angiostrongylus vasorum infections in dogs from Italy, along with the evaluation of the occurrence of intestinal parasites. Fecal samples collected from a total of 2000 dogs living in the majority of the Italian regions were subjected to Baermann examination and flotation. Animals were selected according to a series of criteria to ensure the enrollment of dogs at risk to be infected by nematodes. A binomial logistic regression was performed to detect statistically significant associations between the positivity to Capillaria spp. and A. vasorum and selected epidemiological and clinical variables. Overall, 5.50%, 3.25% and 1.35% of dogs tested positive for C. aerophila, C. boehmi and A. vasorum respectively, with 1.30% of the animals being positive for at least two of them simultaneously. The statistical analysis showed significant associations between cardiorespiratory clinical signs and positivity to C. aerophila (p < 0.001; OR= 5.46; 95% CI: 2.04-14.66), C. boehmi (p < 0.001; OR= 10.38; 95% CI: 3.48-30.92), and A. vasorum (p < 0.001; OR= 17.81; 95% CI: 5.56-56.98). Significant statistical associations between the infection with C. aerophila (p < 0.001; OR= 3.92; 95% CI: 2.09-7.33) and with C. boehmi (p < 0.001; OR= 6.62; 95% CI: 2.64-16.55) and hunting dogs were also detected. Permanent outdoor housing was significantly associated with C. aerophila (p = 0.02; OR= 1.95; 95% CI: 1.14-3.35). Dogs ageing ≥ 5 years showed lower odds of positivity to both C. boehmi (p = 0.04; OR = 0.56; 95% CI: 0.33-0.95) and A. vasorum (p = 0.03; OR = 0.42; 95% CI: 0.18-0.94) than younger dogs. Mixed-breed status was also significantly associated with A. vasorum positivity (p = 0.03; OR = 3.13; 95% CI: 1.06-9.19). Ancylostomatidae (16.15%), Trichuris vulpis (12.45%) and ascarids (7.15%) were the most frequently detected intestinal parasites in the study population. Co-infections by respiratory and intestinal nematodes were found in 7.10% of the dogs, C. aerophila and Ancylostomatidae being the most frequent combination (1.80%). The present results confirm the epidemiological relevance of canine respiratory capillarioses and the established endemic occurrence of A. vasorum in Italy. The frequent detection of respiratory and intestinal nematodes, often in co-infections, emphasizes the importance of routine parasitological screening and of appropriate parasiticides in canine populations of Italy. This is particularly true in dogs who are more prone to be infected by endoparasites as those examined in the present study.