The Canadian Food Inspection Agency (CFIA) has enacted a temporary ban on livestock entering Canada from Texas after the discovery of New World screwworm in a calf. This flesh-eating parasite, which burrows into the skin of its host, has not been reported in the U.S. since the 1960s. The ban applies to all animals, including horses, that have been in Texas within the past 21 days. The CFIA's decision follows U.S. officials' announcement of the parasite's presence, which has been spreading among livestock in Mexico since 2024. Although Canada’s colder climate is not conducive to the long-term establishment of the screwworm fly, the CFIA has urged vigilance among animal owners and veterinarians. They are advised to monitor livestock for symptoms of infestation, such as wounds that worsen over time and emit foul odors. Identification of screwworm infestations must be confirmed by a laboratory, which is obligated to notify the CFIA upon detection.