Canada has imposed a temporary ban on livestock imports from Texas after officials confirmed the presence of New World screwworm parasites [1].
The restriction aims to protect the Canadian agricultural economy from a flesh-eating parasite that poses a severe threat to animal health [2]. A single calf in the La Pryor area of Zavala County, Texas, first tested positive for the parasite on Wednesday, June 5, 2024 [3], [4]. A second calf in the same county was later detected to have the parasite [5].
The Canadian Food Inspection Agency announced the import restrictions on Friday, June 7, 2024 [6]. While some reports suggest the ban applies only to cattle, the agency's announcement indicates the temporary restriction includes both cattle and horses [7].
In response to the outbreak, the U.S. Department of Agriculture began containment efforts in Texas. Officials said they released millions of sterile flies [8] to disrupt the parasite's breeding cycle. Some reports specify that more than two million sterile flies were deployed to manage the spread [9].
New World screwworms are larvae that infest the living flesh of mammals. Because the parasite can cause extensive tissue damage and death in livestock, the CFIA and USDA are coordinating to prevent the parasite from establishing a permanent population in North America [2], [6].
Texas ranchers remain on edge as authorities monitor the affected region in Zavala County [4]. The USDA said it continues to track the movement of livestock to ensure the parasite does not spread to other states or across the border [8].
“Canada has imposed a temporary ban on livestock imports from Texas”
The swift imposition of import bans by Canada highlights the high stakes of transborder agricultural biosecurity. Because screwworms can devastate livestock populations, the use of the Sterile Insect Technique by the USDA is a critical effort to prevent a wider economic crisis for the North American beef and horse industries.
