The U.S. Department of Agriculture (USDA) confirmed a case of New World screwworm in a dog in Cochise County, Arizona, on Oct. 28, 2026. It is the first detection of the parasite in the state.
According to the Arizona Department of Agriculture, a local veterinarian examined the dog on the evening of Oct. 26. The vet found a wound on its back heavily infested with fly larvae. Samples were confirmed at the APHIS National Veterinary Services Laboratories in Ames, Iowa. The dog lives on a ranch in Cochise County. USDA did not say where in the county the ranch is located.
The dog has no travel history. Other livestock on the ranch are to be examined. The dog remains under a veterinarian’s care. Officials are gathering information for an epidemiological investigation with the veterinarian and the owner.
State Veterinarian Ryan Wolker announced restrictions on animal movement and the designation of an infested zone. According to him, about 1 million sterile flies have already been released in the Cochise County area. Wolker also said that although the parasite affects all warm-blooded animals, it is highly treatable.
The Arizona Department of Health Services said no human infections have been reported in the U.S. It described the risk to the general public as very low. Cases in sheep or cattle were previously confirmed in New Mexico and Texas. According to officials, this is the first case in a dog in the U.S.
Animal owners in the area should check their animals for wounds every day. Warning signs include wounds that are growing or oozing, larvae or clusters of eggs in wounds, restlessness in the animal, and changes around the ears, nose and genital area. Any suspected infestation should be reported immediately to a veterinarian, state animal health authorities or USDA.
Source: AZFamily, KJZZ
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