Evaluation of community-based mass dog deworming and public health education for the control of Toxocara spp. infection in household dogs in Vietnam.

Abstract

Toxocara spp. are neglected zoonotic nematodes that commonly infect dogs and represent an important public health concern. However, evidence on community-based control interventions remains limited. This study aimed to compare mass deworming of dogs and cats with public health education in reducing Toxocara spp. infection in household dogs. A community-based controlled intervention study was conducted between February and July 2025 in eight hamlets in Krong Nang district, Dak Lak Province, Vietnam. Four hamlets were assigned to mass deworming of pets with fenbendazole, and four to public health education. Dog fecal samples were collected at baseline and after three months and examined by copromicroscopy and polymerase chain reaction (PCR). The primary outcome was PCR-detected T. canis prevalence, and arithmetic mean infection intensity in eggs per gram (EPG). The analysis included 557 dog observations across baseline and follow-up surveys. After three months, the deworming group showed greater descriptive reductions in copromicroscopy- and PCR-detected Toxocara spp. prevalence and EPG than the education group. The relative reduction in PCR-detected T. canis prevalence was descriptively greater in the deworming group (22.1%, 95% CI: -11.4-47.3) than in the education group (3.3%, 95% CI: -39.2-34.1). However, mixed-effects logistic regression found no statistically significant intervention effect on PCR-detected T. canis infection over the three-month follow-up. Although no statistically significant intervention effect was detected, mass pet deworming showed larger descriptive reductions in Toxocara spp. infection than public health education. Further studies are needed to evaluate integrated strategies combining regular deworming, education, and environmental hygiene, which may help reduce environmental contamination and zoonotic transmission.