Emergency Order Protects Montana Livestock From New World Screwworm

The Montana Department of Livestock has issued an emergency order halting the import of certain animals from states affected by New World Screwworm, following the recent confirmation of the parasite in Texas.

The order, effective immediately, comes after the U.S. Department of Agriculture confirmed a case of the destructive pest in Zavala County on June 3. Officials warn the parasite poses a serious threat to livestock, wildlife and even humans, as its larvae feed on living tissue in open wounds.

State Veterinarian Dr. Tahnee Szymanski said the action was necessary to protect Montana’s livestock industry from what could become a costly and widespread infestation. The pest was eradicated in the United States in 1966, and its reappearance raises concerns about economic and animal health impacts nationwide.

Under the order, animals originating from affected states or designated infestation zones must meet strict requirements before entering Montana. These include obtaining an import permit, undergoing veterinary inspection, receiving approved parasite treatment within a specified timeframe and carrying proper identification and documentation.

Livestock shipments suspected of infection will be denied entry until all animals are treated and free of wounds or infestation.

The restrictions apply broadly to all warm-blooded animals, including cattle, horses, sheep, goats, poultry, pets and wildlife. Additional rules apply to animals coming from specific Texas counties, even if they are outside designated infestation zones.

Officials emphasized that movement of infested animals could accelerate the spread of the parasite, as larvae can develop and spread after dropping to the ground.

The emergency order will remain in place for up to five years but may be revised or lifted sooner. The Montana Board of Livestock is scheduled to review the order at its next meeting on Aug. 27.