High prevalence of gastrointestinal parasites of dogs from Saipan, Northern Mariana Islands, including the zoonotic Ancylostoma ceylanicum

Background: Gastrointestinal (GI) parasites of dogs, including helminths and protozoans, are of substantial relevance to veterinary medicine and public health. Nevertheless, epidemiological data is scarce from many areas around the globe, especially in remote locations. The emergence of novel technologies and diagnostic platforms facilitates comprehensive screening of multiple GI parasites. Our study aims to establish a baseline prevalence for GI parasites in dogs from Saipan, Northern Mariana Islands. Methods: Fecal samples were collected from dogs (n=420) from May to June 2023 during a spay-neuter campaign. Age, sex, ownership status, and residing location were recorded. Frozen samples had total nucleic acids extracted and were molecularly screened for a panel of endoparasites using the KeyScreen ^TM GI Parasite PCR (Antech Diagnostics). Results: Overall, parasites were detected in 267 (63.5%) of canine samples. The most detected parasite genus was Ancylostoma spp. (n=224; 53.3%), followed by Giardia duodenalis (n=67; 15.9%), Trichuris (n=39; 9.2%), Dipylidium (n=25; 5.9%), Toxocara (n=15; 3.5%), Cystoisospora (n=10; 2.3%), and Cryptosporidium (n=5; 1.1%). Assemblages with zoonotic potential of Giardia duodenalis and the SNPs 167Y and 134H in the isotype 1 Beta-tubulin gene associated with benzimidazole-resistance in Ancylostoma caninum were not detected. Risk factors significantly associated with infection were age, district, and ownership with Trichuris; age and ownership with Ancylostoma , Giardia , and Dipylidium ; and ownership with Toxocara and Cystoisospora . Hookworm positive samples were further characterized to species level using qPCR. Overall, A. caninum and A. ceylanicum / A. duodenale were confirmed in 196 (46.7%) and 57 (13.5%) dogs, respectively. Further sequencing confirmed the presence of the zoonotic A. ceylanicum in at least 21 samples; approximately 5% of the dog population, which were geographically distributed across all districts. Conclusion: To our knowledge, our study is the first to provide epidemiological data on canine gastrointestinal parasites for Saipan. The high prevalence of multiple parasites of One Health importance reinforces the need for surveillance and implementation of strategies for prevention and control island-wide, especially those targeting A. ceylanicum , a zoonotic hookworm that may establish patent infections in both companion animals and humans.