Presence of Gasterophilus (Leach, 1817) (Díptera: Oestridae) in horses in Rio Grande do Sul State, Brazil

with the purpose of verify the presence of larvae from the genus gasterophilus in the rio grande do sul state, a study was undertaken using 395 horses taken to slaughter in the city of pelotas. the material analysis revealed that 126 animals (31,90%) presented infection, with 100 animals (25, infected by gasterophilus nasalis, and 47 animals (11,90%) infected by g intestinalis. these results also represent the first report of the definite establishment of g intestinalis as a horse parasite in brazil. the probable implications of g. intestinalis occurrence in brazil are discussed.