The Canadian Food Inspection Agency restricts imports after the flesh-eating parasite is found in a calf in Texas
Category: U.S. News
On June 5, 2026, the Canadian Food Inspection Agency (CFIA) announced a temporary ban on livestock imports from Texas following the detection of New World screwworm in a calf. This marks the first time the parasite has been confirmed in the United States since the 1960s, prompting immediate action to safeguard Canadian agriculture.
The CFIA's decision prohibits animals, including horses, that have been in Texas within the past 21 days from entering Canada. The move comes in response to U.S. officials' identification of the parasite, which is endemic to South America and the Caribbean, and has recently spread among livestock in Mexico.
According to the CFIA, the larvae of the screwworm fly burrow into the skin of warm-blooded animals, feeding on living tissue. In rare cases, humans can also be affected. The agency emphasized that the colder Canadian climate is not conducive to the long-term establishment of the parasite, but it can survive short periods during the summer months.
In a statement, the CFIA urged animal owners and veterinarians to remain vigilant for signs of infestation. "A wound that worsens over time and is accompanied by discharge or foul odor is also usually observed," the agency noted. New World screwworm is classified as an immediately notifiable disease under the Health of Animals Act, meaning that suspected cases must be reported to a veterinarian, who can confirm identification through laboratory testing.
The discovery of the screwworm in Texas has raised alarms within the agricultural community, particularly as the parasite poses serious risks to livestock health and productivity. The U.S. Department of Agriculture (USDA) reported that a three-week-old calf in South Texas was found with screwworm larvae in its umbilical area, marking the first case in the country linked to an outbreak that has been spreading in Mexico since 2024. A second case was confirmed shortly thereafter in a one-month-old calf just 5.6 miles away.
In response to the outbreak, Texas Governor Greg Abbott declared a state of disaster on June 5. His spokesperson criticized Canada's ban, stating that it was an overreaction. "This pest affects live animals and does not impact inspected Texas beef," Andrew Mahaleris said. He argued that Texas and USDA officials are taking appropriate measures to contain the parasite's spread in a limited area of South Texas.
The CFIA's announcement is part of broader precautionary measures being implemented across several U.S. states to limit the risk of the parasite's spread. The agency is working closely with American officials to monitor developments and adjust measures as necessary. The U.S. had previously closed southern ports of entry with Mexico to livestock trade in July 2025 to prevent the introduction of screwworm into the country.
The New World screwworm was eradicated from the United States in 1966, and by the mid-2000s, it was eliminated from North and Central America. The successful eradication program involved the release of sterile male flies to reduce the population of the parasite. This method has been revived in response to the current outbreak, with American officials working to expand the use of sterile male screwworm flies to combat the resurgence.
As climate change continues to alter weather patterns, concerns grow that the range of screwworm flies may expand, especially in warmer regions. The USDA has faced scrutiny for its handling of the situation, with some critics alleging that budget cuts and slow responses contributed to the parasite's re-entry into the U.S. agriculture system. Agriculture Secretary Brooke Rollins has attributed the issue to previous administrations, claiming that current efforts are focused on controlling the outbreak.
In Canada, the CFIA's proactive measures aim to prevent a similar outbreak. The agency has emphasized the importance of vigilance among livestock owners and veterinarians, noting that the parasite can create painful and often deadly wounds in affected animals. The CFIA has also reiterated that the risk of establishing a permanent population in Canada remains low due to the country's climate.
The CFIA will continue to assess the situation in collaboration with U.S. officials, monitoring the spread of the screwworm and adjusting import restrictions as necessary. The agency's current ban is a precautionary step aimed at protecting Canadian livestock from potential infestation.
As the situation develops, both Canadian and U.S. agricultural sectors are on high alert. The economic implications of a screwworm outbreak could be severe, particularly for Texas, where the cattle industry is valued at $15.5 billion. The USDA's efforts to contain the parasite will be closely watched, as any failure to manage the outbreak could have cascading effects on trade and livestock health.
Animal owners are encouraged to report any suspected cases of screwworm infestation to their veterinarians immediately. With the threat of the parasite now recognized, the agricultural community in both countries must remain vigilant to prevent a crisis that could affect livestock health and agricultural productivity across North America.