Visceral toxocariasis is a neglected parasitic zoonosis that occurs through the ingestion of embryonated Toxocara spp. eggs. A wide range of animal species can act as paratenic hosts for this ascarid. The main risk factor for humans is the ingestion of the eggs from contaminated soil; however, infection can also occur through the ingestion of contaminated raw or undercooked infected meat from paratenic hosts. The aim of this study was to verify the presence of Toxocara spp.-specific antibodies in sheep and to determine the risk factors associated with the infection of sheep in Rio Grande do Sul (a major sheep-producing and sheep-consuming state) in southern Brazil. Serum samples collected from 1,642 sheep were tested using an IgG enzyme-linked immunosorbent assay based on the excretory-secretory Toxocara canis antigen. Seroprevalence was 29.0% (477/1,642), and every farm included in the study contained at least one seropositive animal. These results indicate that T. canis infection is widely distributed among sheep herds in Rio Grande do Sul and that it represents a potential risk to human health.