Zoonotic Parasites in Stray Dogs and Their Public Health Implications

Background: Stray dogs are important reservoirs of zoonotic intestinal parasites, particularly in urban settings where close human–animal contact, poor waste disposal, and environmental contamination may facilitate transmission. Limited field-based data are available from Pakistan regarding the parasitic burden of stray dogs in public and healthcare-adjacent environments. Objective: This study aimed to determine the prevalence and distribution of intestinal parasites among stray dogs in and around a tertiary care hospital setting in Punjab, Pakistan, with emphasis on parasites of zoonotic importance. Methods: A cross-sectional field and laboratory-based study was conducted over six months. Fresh fecal samples were collected from 210 stray dogs from hospital surroundings, residential streets, public parks, and waste-disposal areas. Samples were examined using macroscopic assessment, direct wet mount microscopy, zinc sulfate flotation, formalin–ether sedimentation, and modified McMaster egg-counting techniques. Parasites were identified morphologically, and helminth parasite load was categorized as low, moderate, or high. Data were analyzed using descriptive statistics, and associations with age group and sampling location were assessed using chi-square testing where applicable. Results: Overall, 134 of 210 fecal samples were positive for one or more intestinal parasites, giving a prevalence of 63.8%. Mono-parasitic infections were detected in 89 positive samples (66.4%), while mixed infections were observed in 45 positive samples (33.6%). The most frequently identified parasites were Toxocara spp. 46 (21.9%) and Ancylostoma spp. 39 (18.6%), followed by Giardia duodenalis 24 (11.4%), Dipylidium caninum 21 (10.0%), Trichuris vulpis 18 (8.6%), Cryptosporidium spp. 17 (8.1%), Taenia spp. 13 (6.2%), and Strongyloides spp. 11 (5.2%). Toxocara spp. was more frequent among juveniles, while the highest location-specific prevalence was observed at waste-disposal sites (72.4%). Conclusion: Stray dogs in the study area harbored a high burden of intestinal parasites, including several species of zoonotic relevance. These findings highlight the need for integrated One Health interventions, including stray-dog management, deworming strategies, improved waste disposal, environmental sanitation, and community awareness to reduce potential zoonotic exposure