New Mexico detects second case of New World screw worm in Grant County

New Mexico officials and ranchers are addressing the threat of New World screw worm after the parasite was detected in a horse in Grant County, marking the state’s second case this year.

“To have a screw incident in Grant County, probably at least 100 miles north of the border — that came as a bit of a surprise,” said Tom Paterson, president of the New Mexico Cattle Growers Association.

This detection comes months after health officials found New World screw worm in a dog in Lea County in June.

“Whether it’s livestock, or whether it’s wildlife, it’s an animal welfare issue,” Paterson said.

The Santa Teresa cattle crossing, which has been closed for nearly two years following the detection of New World screw worm in neighboring Mexico, is set to reopen this Thursday. The crossing previously saw between 3,000 and 3,500 cattle pass through daily.

“Santa Teresa is the crown jewel of the cattle crossings,” said Gerardo Fierro, executive director of the New Mexico Border Authority. “[It’s] the biggest cattle crossing in the U.S., Mexico border and Canada.”

The closure of Santa Teresa, along with a second closure at the Columbus port, has resulted in significant losses for New Mexico cattle ranchers.

“For the value of cattle being traded at both Santa Teresa and Columbus — just for last year — was a little bit over $1 billion,” Fierro said. “With the cattle prices as high as today, it could go all the way up to $2 billion.”

To combat the spread of the disease, the USDA has been releasing weekly shipments of 1.8 million sterile flies at the border.

“This is a precaution to have a lot of flies being released right now,” Fierro said. “When the bad flies come, these are already in place, and they can start cutting the cycle.”

Despite the recent detection in Grant County, some ranchers remain confident that the reopening of the Santa Teresa crossing will not pose a risk.

“Given the extensive protocols in place for for examining them, for treating them, for dipping them [and] for giving them shots — those are not the cattle that are going to be bringing New World screw room in the United States,” Paterson said.

Ranchers are also hopeful that cooling weather patterns will help keep screw worm flies away from livestock. If all goes smoothly, the Columbus crossing is expected to reopen in about a month.

For livestock infected with New World screw worm, the FDA has authorized the use of ivermectin for treatment.