The threat of an invasive screw worm species could be harmful to Minnesota's pets and wildlife.
Experts are urging residents to say alert for the New World screwworm, an aggressive fly whose maggots feed on living flesh.
While the species was previously eradicated from the U.S., recent outbreaks in Mexico are raising concerns for reintroduction as Minnesota's summers become warm enough for the pest to thrive.
State Veterinarian Dr. Brian Hoefs says right now these parasites are headed north.
"Last reports are about 370 miles from the Mexico-Texas border," says Hoefs. "This tells us that this parasite is on the move and it's a parasite that infects all warm-blooded species."
The Minnesota Board of Animal Health warns that any animal - especially livestock that has traveled through effected areas - with open wounds or maggots should be taken into be evaluated.
"Animals might be more irritable. They might have an area that's sore and painful to the touch," explains Hoefs. "They might avoid, you know, flinch if you rub your hand across a bump on their side. That could be an indication."
Hoefs says recognizing signs like maggots in wounds is key to preventing its spread.
Meanwhile, the U.S. government plans to open what amounts to a fly factory by the end of the year, announcing its intent back in June to breed millions of the insects in Texas near the border with Mexico as part of an effort to keep a flesh-eating parasite from infesting American cattle.
Agriculture Secretary Brooke Rollins said sterile male New World screwworm flies bred at the $8.5 million facility would be released into the wild to mate with females and prevent them from laying the eggs in wounds that become flesh-eating larva.
It would be only the second facility for breeding such flies in the Western Hemisphere, joining one in Panama that had largely kept the flies from migrating further north until last year.
The U.S. bred and released sterile New World screwworm flies into the wild decades ago, and it was largely banished from the country in the 1960s. Previously, it had been an annual scourge for cattle ranchers and dairy farmers, particularly in the Southeast.
While there are treatments for New World screwworm infestations, cattle industry officials still worry that farmers and ranchers could see huge economic losses. They, agriculture officials and scientists also said the larva can infest any mammal, including household pets, and it has occasionally been seen in humans.