One hundred and two stray dogs in Ejungbu City of Kyunggi-Do, Korea were examined to reveal out the degree of natural helminthic infection of small intestine. Helminthes were collected at autopsy, by scraping the intestinal contents. The collected worms were classified by their morphological characteristics. Out of 102 examined, 72 dogs were infected with any helminthes. The common helminthes were Dipylidium caninum (47 percent), Ancylostoma caninum (26 percent), Toxascaris leonina (16 percent) and Toxocara canis (13 percent). Taenia pisiformis (9 percent), Echinostoma hortense (4 percent), E. cinetorchis (2 percent), Spirometra mansoni (2 percent) were also found. One dog was incidentally found to be infected with Clonorchis sinensis. The prevalence of Toxascaris leonina was relatively high in this study over Toxocara canis, and its significance was discussed. Dogs were firstly described as the reservoir hosts of Echinostoma hortense and E. cinetorchis in Korea.
