Introduction. Toxocara canis is a zoonotic nematode of global importance that causes visceral and ocular larva migrans in humans. In Mexico, large populations of stray and free-roaming dogs increase environmental contamination with infective eggs, yet no previous systematic synthesis of prevalence data exists. This review aimed to determine the prevalence of T. canis infection in dogs across Mexico and identify research gaps.
Methods. Following PRISMA 2020 guidelines, systematic searches were conducted in PubMed and Scopus (up to March 2026) using the terms (“Toxocara canis” OR Toxocara) AND (dog OR dogs OR canine) AND (Mexico OR México) AND (prevalence OR infection OR seroprevalence). Inclusion criteria were original studies reporting quantitative prevalence (coprological, serological, or necropsy) in dogs in any Mexican region. Two independent reviewers screened titles/abstracts and extracted data on location, sample size, diagnostic method, and prevalence.
Results. Of 41 records identified in PubMed (and equivalent in Scopus), only three primary studies met inclusion criteria after duplicate removal and full-text assessment (n=544 dogs total). Prevalence ranged widely: 66.7% (serology, IHAT; stray dogs, Mexico City, 2008; n=141), 15.1% (coprology; stray dogs, Querétaro, 2011; n=378), and 8% (coprology; free-roaming dogs, Tulum, Quintana Roo, 2022; n=25). One additional regional review (2020) reported a broader Latin American range of 0–87%, with the highest values in young stray dogs. No meta-analysis was possible due to high heterogeneity in methods and populations.
Conclusions. Toxocara canis prevalence in Mexican dogs varies from 8% to 66.7%, being consistently higher in stray populations. These findings underscore the urgent need for nationwide control programs, routine deworming, and public health education. Future studies should use standardized diagnostics and include owned dogs to better estimate zoonotic risk.