OTTAWA, ON, June 5, 2026 /CNW/ – Following a confirmed finding of New World screwworm in a calf in Texas, the Canadian Food Inspection Agency (CFIA) announced today that it will implement temporary import restrictions on livestock, including horses, from entering Canada from affected areas. Animals that originate from or were present in the State of Texas within 21 days prior to border crossing will not be accepted into Canada. Several U.S. states have also taken precautionary actions to mitigate the risk of spread. The CFIA will continue to work closely with U.S. counterparts to assess developments and adjust measures as needed.
The flesh-eating larvae of this parasitic fly threatens the lives of its host animals. 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.
Animals owners and veterinarians are encouraged to be on the look out for signs of screwworm infestations in livestock. A wound that worsens over time and is accompanied by discharge or foul odour is also usually observed. For Canadians travelling to Texas with their companion pets, they are encouraged to remain vigilant and inspect their pets regularly for any signs.
In Canada, New World screwworm is an immediately notifiable disease under the Health of Animals Act. Owners should contact their veterinarian if they suspect signs of New World screwworm as identification of the fly can be confirmed only with laboratory testing. Laboratories are required to contact the CFIA regarding the suspicion or confirmation of infestation.
Quick Facts
- The New World screwworm is a parasitic fly whose larvae (maggots) eat the living tissue of warm-blooded animals. When screwworm fly larvae (maggots) burrow into the flesh of a living animal, they cause serious, often deadly damage.
- Screwworms can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people.
- New World screwworm is not found in Canada and cannot survive winter temperatures in Canada. The flies prefer hot, humid environments with an air temperature between 25-30 degrees Celsius.
- It is endemic to South American and Caribbean countries.
- Mexico has reported cases of New World screwworm as well. Currently, Canada does not allow the importation of cattle, bison, sheep, goats, cervids and swine from Mexico and stringent import conditions are in place for import of horses from Mexico to prevent introduction of animal disease into Canada.
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Each day, hard-working Canadian Food Inspection Agency employees–including inspectors, veterinarians, and scientists–inspect food for safety risks, work to protect plants from pests and invasive species, and respond to animal diseases that could threaten Canada’s animal resource base and human health. Guided by science-based decision-making and modern regulations, the Agency verifies that food sold in Canada is safe while supporting access to international markets for our high-quality agricultural products. To learn more, visit Canadian Food Inspection Agency – inspection.canada.ca.
SOURCE Canadian Food Inspection Agency (CFIA)
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