New World Screwworm Fears Trigger Border Limits Before Calgary Stampede

The recent detection of New World screwworm in Texas has prompted closed borders for livestock movements across North America. Among those measures are restrictions affecting the movement of livestock between the United States and Canada, raising questions about potential impacts on major agricultural and rodeo events, including the Calgary Stampede.

New World screwworm, Cochliomyia hominivorax, is a parasitic fly whose larvae feed on the living tissue of warm blooded animals. The pest poses a serious threat to livestock industries because infestations can cause severe injury, illness, and death if left untreated.

In response to concerns about the spread of the New World Screwworm, livestock crossing the U.S.-Canada border may be subject to additional health requirements, including quarantine periods and inspections. Current restrictions require certain animals to meet strict entry protocols before being permitted to cross international borders. Canadian officials announced late last week that livestock and horses entering Canada cannot have been in Texas within 21 days before crossing the border.

Several states, including Florida, Georgia, Tennessee, and Montana, have strengthened livestock entry requirements for animals coming from Texas. The heightened measures include additional health papers and protocols as officials work to limit the spread of New World screwworm.

Real AG Radio host, Shaun Haney, went on RFD TV speaking out about the New World Screwworm and how it may affect the U.S.-Canada border crossings. Haney said the measures are similar to restrictions already applied to livestock entering Canada from Mexico and emphasized that the policy is intended to manage risk based on animal health science rather than halt all livestock imports from the United States.

He added that Canadian producers have expressed concern for Texas ranchers facing quarantines, livestock movement restrictions, and the economic challenges associated with New World screwworm. While the likelihood of the pest becoming established in Canada is considered low due to the country's climate, the situation remains a topic of interest among livestock producers.

Haney also addressed questions surrounding cross-border livestock movement and major events such as the Calgary Stampede. Although some industry members initially questioned whether the restrictions could affect horses and livestock traveling to the event, he said organizers do not currently expect disruptions to this year's Calgary Stampede. 

The Calgary Stampede, often referred to as the World's Largest Outdoor Rodeo, is scheduled for July 3–12. Under Canada's current 21-day livestock restriction, contestants competing at the Stampede could face scheduling challenges if they also plan to use the same horse at Texas rodeos leading up to the event. The Stampede falls during a busy stretch of the summer rodeo season, overlapping with several major PRCA rodeos in Texas, including El Paso, West of the Pecos, Mesquite, and Belton. For competitors who rely on a single horse throughout the season, the 21-day restriction could make it difficult to compete at both Texas rodeos and the Calgary Stampede within the same timeframe.

The United States has 7 total active cases of the New World Screwworm since the eradication decades ago. Texas has 6 recorded active cases in cattle and a goat, in counties La Salle, Gillespie, Zavala and Edwards. New Mexico has one reported active cases in a dog, in Lea county.

All recorded cases are in domesticated animals rather than in wildlife. The USDA has placed fly traps as well, and is working to trap and identify any wild Screwworm flies. So far, no fly trap detections have been made.