Occurrence of endoparasites in dogs and cats upon admission to an Austrian animal shelter

Monitoring the distribution and prevalence of companion animal endoparasites is essential due to their impact on animal health and potential zoonotic risks to humans. The aim of this study was to assess the occurrence of endoparasites in dogs and cats submitted to an Austrian animal shelter. We examined the feces of 297 dogs and of 158 cats, using a combined flotation-sedimentation technique, the Baermann technique and Giardia and Cryptosporidium antigen tests. Multilocus genotyping was performed on Giardia -positive samples. Overall endoparasite occurrence was 21.5% in dogs and 19.6% in cats. The most frequent endoparasite in dogs was Trichuris vulpis (11.8%), followed by Giardia duodenalis (8.4%), hookworms (3.0%), Toxocara canis (2.4%), Cystoisospora ohioensis -complex (1.0%), Capillaria spp. (1.0%), Cystoisospora canis (0.3%), and Toxascaris leonina (0.3%). In cats, G. duodenalis (12.0%), Toxocara cati (4.4%), Cystoisopora felis (3.2%), Aelurostrongylus abstrusus (1.2%), Cystoisospora rivolta (0.6%), and hookworms (0.6%) were detected. Coinfections with endoparasites occurred in 25.0% of positive dogs and 15.6% of positive cats. In dogs, the most common G. duodenalis assemblage identified was BIV (60.0%), followed by D (50.0%), C (35.0%), and AII (5.0%). In cats, assemblage F was the most frequent (60.0%), followed by BIV (33.3%). Coinfections with multiple assemblages occurred in 65% of dogs but not in cats. In dogs, parasite occurrence was significantly associated with young age and unphysiological fecal consistency, the latter association was also found in cats. Dogs and cats admitted to this shelter showed a lower occurrence of endoparasites compared to other European studies. The presence of zoonotic Giardia assemblages A and B underscores the need for effective control to protect staff and future owners. Beyond enhancing diagnostic sensitivity through combined flotation and antigen testing at admission, the integration of standardized deworming and stringent hygiene measures is essential to effectively suppress parasite transmission and mitigate risks to both animal and human health.