Factors affecting the occurrence of gastrointestinal parasites and lungworm in dogs and assessment of antiparasitic drug use patterns

Dogs are hosts of parasites with different pathogenicities and zoonotic risks. The aim of our study was to assess factors that could affect the occurrence of endoparasitic infections in dogs using questionnaires for owners and examining canine faeces. Based on the responses of dog owners, we evaluated ways of the preventive and therapeutic use of antiparasitic drugs. One faecal sample was obtained from each dog (391 samples total), and then examined by flotation, larvoscopic, and polymerase chain reaction (PCR) methods. We focused on zoonotic tapeworms Echinococcus multilocularis and Taenia crassiceps. The answers in the dog owners’ questionnaires showed that owners most often dewormed their dogs irregularly (96.4%), namely, twice a year (24.3%). In coprological examinations the following parasites were detected: Giardia spp., Cystoisospora ohioensis complex, Neospora caninum/Hammondia heydorni, Toxocara canis, Toxascaris leonina, Capillaria spp., Trichuris spp., Angiostrongylus vasorum, Crenosoma vulpis, Ancylostoma spp. and Taenia spp. A total of 4 out of 391 PCR investigated samples of faeces were positive for DNA of Taenia species. Sequences were obtained for 3 of them, confirming 100% identity with T. crassiceps. The zoonotic helminths Toxocara canis were the more prevalent species (9.3%, 4.3%, 1.9% group A, B, C). We consider the presence of T. crassiceps in 3 dog faecal samples to be serious due to its zoonotic potential. Data collected within this study showed that the prevention against endoparasites carried out at the breeders’ discretion is insufficient to ensure the health of their dogs or to cover the risk of zoonotic transmission.