US flesh-eating parasite spreads to New Mexico; Canada halts Texas livestock imports

A flesh-eating parasite, the New World screwworm, has expanded its reach across state lines, with U.S. agriculture officials announcing three new cases, including one in New Mexico. This marks a significant development as the parasite, which feeds on live tissue, was previously confirmed in Texas.

In response to the growing concern, Canada has imposed a temporary ban on importing cattle, horses, and other livestock from Texas. The screwworm fly lays its eggs in open wounds of animals, but can also infect wildlife, pets, and occasionally humans. While the U.S. has been releasing sterile flies to combat the pest since its re-emergence in late 2024, the recent cases highlight the ongoing challenge.

“

Scientists expect new cases in the coming days and weeks, but this does not mean the screwworm is spreading rapidly.

Currently, there are five confirmed cases: three calves and a goat in Texas, and a dog in New Mexico. The dog's travel history is under investigation. Entomologists anticipate more cases in the coming weeks, though they do not indicate a rapid spread. The potential impact on the millions of wild white-tailed deer in Texas is a significant concern for scientists.

Despite the parasite's ability to attack live cattle, it does not affect meat or produce. U.S. Secretary of Agriculture Brooke Rollins stated the goal is to have enough sterile flies to prevent a recurrence by 2027, following efforts to eliminate most screwworms over the winter. The current outbreak has not significantly impacted beef prices, which are already near historic highs due to a reduced U.S. cattle population.

“

The goal is to have enough sterile flies to prevent these pests from making a comeback in 2027, after killing most of the screwworms over the winter.