New World screwworm case reported in Arizona dog

Arizona reported its first case of New World screwworm on Wednesday, making it the third state to be impacted by the parasite.

The confirmed case was found in a domestic dog in Cochise County, Ariz., which shares a border with Mexico, according to a press release from the U.S. Department of Agriculture.

The state’s Department of Agriculture, which also confirmed the case in a Wednesday press release , noted the discovery was made when a veterinarian examined the dog on Oct. 26 and identified a maggot-infested wound on the animal’s back. Authorities conducted scientific testing, which verified the species.

“We have been preparing for this possibility for a long while and are acting swiftly,” State Veterinarian Ryan Wolker said in the release. “Because of the extensive outreach, coordination, and surveillance already in place, Arizona producers, veterinarians, and pet owners know what to look for and how to report suspected cases.”

The animal is under veterinary care, and the state’s department is working with the owner and the attending veterinarian to gather further information, according to the release.

“New World screwworm is a serious pest that affects livestock, pets, wildlife, and, less commonly, people,” the USDA release said. “The larvae feed on living tissue and can cause severe wounds, animal suffering, and significant economic impacts if not detected and treated quickly.”

The USDA has confirmed 71 cases of screwworm in three states — Texas, New Mexico and, most recently, Arizona. Out of those cases, 18 remain active as of Thursday. There is only one case that is associated with U.S. wildlife while the rest are in domestic animals.

The New World screwworm is a parasitic fly that can enter animals through open wounds and feed on living tissue. The first case of the flesh-eating parasite was reported in June in Zavala County, Texas.