The Idaho State Department of Agriculture (ISDA) announced additional state entry requirements for animals in response to New World screwworm (NWS) detections in Texas and New Mexico.

On June 3, 2026, the USDA confirmed the first U.S. case of NWS in Zavala County, Texas. NWS is a serious pest that threatens livestock, pets, wildlife and, in rare cases, people. The larvae burrow into the living tissue of animals, causing severe wounds, animal suffering and significant economic losses.

To protect Idaho’s livestock industry and trade interests, as well as the interests of all warm-blooded animals including pets, the ISDA has implemented an administrative order restricting entry of animals from states with NWS infestations.

For all warm-blooded animals including but not limited to all livestock (e.g., cattle, horses, goats, poultry) and all companion animals (e.g., dogs, cats, rabbits, birds) moving from a designated NWS-infested zone, a certificate of veterinary inspection (CVI) issued within five days prior to movement into Idaho and a copy of the movement permit from the state of origin that authorizes the animals to leave the infested zone are required.

For all warm-blooded animals originating from a state where NWS has been detected, but outside a designated NWS-infested zone, a CVI issued within five days prior to movement into Idaho is required.

“Idaho has been preparing for the possibility of New World screwworm reaching the United States, and we are well positioned to respond,” said Chanel Tewalt, ISDA director. “We are coordinating closely with USDA officials and our counterparts across the West. These state-entry requirements reinforce the critical role that pet owners, livestock producers and animal health professionals play in helping the state respond to the threat posed by New World screwworm.”

“ISDA is specifically urging pet owners to avoid traveling with their companion animals in states where NWS has been identified,” said Scott Leibsle, Idaho state veterinarian. “Dogs and cats are just as susceptible to the pest as livestock, but pet owners may be less aware of the importance of thoroughly inspecting their pets for fly larvae that are very small and easy to miss. Owners who do decide to travel with their pets to states affected by NWS will be required to get a health certificate from a veterinarian in that state within five days of their return to Idaho.”

Anyone who suspects a NWS infestation should immediately contact their veterinarian. NWS is a mandatory reportable disease.

In addition to the requirements above, all existing importation requirements for animals eligible for entry into Idaho found in Idaho Department of Agriculture's Rules Governing the Importation of Animals (IDAPA 02.04.21) remain in place, unless modified by this order.

For the full administrative order and more information, visit the Idaho State Department of Agriculture website or contact ISDA Animal Industries Division at (208) 332-8540.

A map of the infested zones in the U.S. can be found at the USDA Animal and Plant Health Inspection Service website.

—From an Idaho State Department of Agriculture news release