Canada is temporarily blocking imports of several live animals from Texas as concerns grow over the spread of the New World screwworm.
The Canadian Food Inspection Agency (CFIA) announced it is immediately suspending imports of horses, pigs, cattle, bison, sheep, goats, deer, elk, moose, llamas and other susceptible animals from Texas.
Animals from other states can still enter Canada, as long as they have not lived in or traveled through Texas within the previous 21 days.
The move comes as Texas continues to battle an outbreak of the flesh-eating parasite. Since the first infestation was confirmed in South Texas in June, the number of cases has grown to 34 as of July 10.
According to the U.S. Department of Agriculture, accredited veterinarians must now certify whether animals being exported have been in a state affected by the New World screwworm. Shipments that do not include that information will be turned away at the Canadian border.
In a statement, the CFIA said it will continue working with U.S. officials while monitoring the situation.
"While our colder climate is not hospitable for the long-term establishment of the fly in Canada, they can survive shorter periods of time in the summer months. Taking this action now is an appropriate risk mitigation measure to prevent its introduction and protect animal health."
The Texas Animal Health Commission said last month that small wildlife and rodents, including armadillos, opossums and rabbits, could be helping spread the pest.
Exactly how the New World screwworm first made its way into Texas is still unclear. The Texas Parks and Wildlife Department says the source of the first case remains under investigation, and other animal health experts say it's still unknown what allowed the parasite to cross the Texas-Mexico border.
The USDA shut down all southern ports of entry for livestock imports from Mexico in May 2025, and they have remained closed ever since.
Officials say the biggest challenge now is stopping the outbreak. Experts estimate about 500 million sterile flies need to be released every week to wipe out the pest. Right now, the U.S. is producing about 100 million sterile flies each week at a facility in Panama.
