Flesh-Eating Parasite Spreads: Canada Bans Texas Livestock

Canada has implemented temporary import restrictions on livestock, including horses, originating from parts of Texas due to the confirmed presence of the New World Screwworm (NWS) in the U.S. As of Wednesday, June 10, 2026, six cases have been identified across Texas and New Mexico, affecting animals like cattle, goats, and a domestic dog.

The Canadian Food Inspection Agency (CFIA) stated that animals present in Texas within 21 days prior to border crossing will be denied entry into Canada. While Canada's colder climate limits the fly's long-term establishment, it can survive shorter periods during summer months, necessitating this preventative measure.

The NWS is a parasitic fly whose larvae infest open wounds on animals and humans, feeding on living tissue. Infections can lead to severe wounds, infections, and even death if untreated. While primarily affecting livestock, human cases have occurred, including a Canadian traveler who contracted the infection after visiting Costa Rica.

Experts have been monitoring the growing NWS threat, noting a significant increase in detections beyond Central America. In Panama, cases surged from an average of 25 annually to over 6,500 in 2023. As of June 8, 2026, over 185,000 animal cases and 2,100 human cases have been reported in Mexico and Central America.

While NWS is not currently found in Canada, travellers heading south are advised to take precautions, as the parasite's spread is expanding. There are no preventative vaccines or medications; however, suspected infections require immediate veterinary or medical attention for treatment involving larval extraction and antibiotics.