'Overreaction'? Canada bars Texas livestock over New World screwworm

Canada’s Canadian Food Inspection Agency announced a temporary ban on livestock imports from Texas on June 5, citing the detection of New World screwworm, a parasitic infection spread by flies that lay eggs in open wounds of warm-blooded animals. The larvae burrow into flesh, causing severe and potentially deadly damage. The ban applies to animals from Texas within 21 days of entry, following the U.S. Department of Agriculture’s confirmation of two infected calves—a 3-week-old and a 1-month-old—detected on June 3 and June 5, respectively. The parasite, eradicated from the U.S. decades ago, has reemerged near the Texas-Mexico border, threatening the state’s $15.5 billion cattle industry. Canada previously banned livestock imports from Mexico to prevent screwworm spread and remains the U.S.’s largest agricultural importer, with Texas as the top beef producer. The agency stated it would adjust measures as the situation evolves, collaborating with U.S. officials. Texas Governor Greg Abbott declared a state of disaster on June 5, calling the screwworm outbreak an ‘imminent threat.’ Abbott’s spokesperson, Andrew Mahaleris, criticized Canada’s ban as an overreaction, asserting that Texas and the USDA are actively containing the outbreak in South Texas. Mahaleris noted that the parasite only affects live animals, not inspected Texas beef. New World screwworm flies, about the size of a housefly, lay eggs in wounds or body openings, leading to painful, foul-smelling infections. Larvae feed on living tissue before pupating in soil, emerging as flies to restart the cycle. The CDC warns of serious secondary infections or illnesses, emphasizing the parasite’s destructive potential. Canada’s move follows its existing restrictions on Mexican livestock and reflects concerns over the parasite’s rapid spread. The U.S. and Texas are implementing eradication strategies, but Canada’s ban highlights the economic and agricultural stakes for both countries.