# New World Screwworm Confirmed in Arizona Dog, Raising Concerns for Nevada Pet Owners Source: https://dogfriendlylasvegas.com/dog-news/local-dog-news/new-world-screwworm-confirmed-in-arizona-dog-raising-concerns-for-nevada-pet-owners/ Published: 2026-11-02 --- The confirmation of New World screwworm in a dog in Arizona marks a new development in the ongoing U.S. outbreak, bringing the serious animal health threat closer to Nevada. The U.S. Department of Agriculture (USDA) announced October 28th that testing confirmed the infestation in Cochise County, Arizona, the first detection of New World screwworm in the state. Although federal health officials say the current risk to people and animals in the United States remains very low, the detection is an important reminder for Nevada pet owners, particularly those who travel with their dogs or visit areas where cases have been reported. New World screwworm can affect dogs, livestock and wildlife, and infestations can cause severe injury if they are not identified and treated promptly. The USDA’s Animal and Plant Health Inspection Service (APHIS) confirmed the case through its National Veterinary Services Laboratories in Ames, Iowa. The agency is coordinating with the Arizona Department of Agriculture on response efforts. ## What Is New World Screwworm? New World screwworm is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals. Unlike many maggots that feed on dead tissue, screwworm larvae can invade open wounds and cause serious damage as they grow. Even relatively small wounds can become dangerous if an infestation goes unnoticed. Animals may develop draining or enlarging wounds, and larvae or egg masses may be visible in affected areas. Infestations can also occur around body openings, including the ears, nose and genital area, as well as around the umbilicus in young animals. Dogs and cats are among the animals that can be affected, alongside livestock and wildlife. People can also be infested, although the Centers for Disease Control and Prevention (CDC) says the current risk to the public in the United States is very low. There have been no reported human infestations acquired within the United States during the current outbreak. ## Arizona Detection Expands the U.S. Response Following the Arizona confirmation, APHIS and state animal health officials are implementing response measures that include establishing a 20-kilometer infested zone around the detection, restricting animal movements within the affected area, increasing surveillance and trapping, releasing sterile flies, and providing targeted outreach to veterinarians, livestock producers and local communities. These measures are designed to detect additional cases and limit the spread of the pest. As of the information provided by USDA and CDC in late October, confirmed animal detections in the current U.S. outbreak have been reported in Arizona, New Mexico and Texas. The situation continues to evolve, and the USDA maintains a public dashboard with confirmed detections and current response information. The outbreak began expanding through Central America and Mexico after cases re-emerged in Panama and Costa Rica in 2023. Since then, animal cases have been reported across the region, including in livestock, pets and wildlife. The United States confirmed its first animal case in the current outbreak on June 3rd, 2026. ## What Nevada Dog Owners Should Know Nevada has been part of the broader conversation about screwworm-related travel restrictions, particularly as animal shelters and rescue organizations transport dogs across state lines. Dog Friendly Las Vegas previously reported on the changing landscape in its July 20th article, [“Screwworm Cases Reach 32 as States Tighten Dog Travel Rules, but Nevada Has No Order of Its Own,”](https://dogfriendlylasvegas.com/dog-news/local-dog-news/screwworm-cases-reach-32-as-states-tighten-dog-travel-rules-but-nevada-has-no-order-of-its-own/) and its August 6th coverage, [“Screwworm Travel Rules Are Now Slowing Shelter Dog Transports Nationwide, With Case Count Topping 40.”](https://dogfriendlylasvegas.com/dog-news/local-dog-news/screwworm-travel-rules-are-now-slowing-shelter-dog-transports-nationwide-with-case-count-topping-40/) The Arizona detection makes it especially important for anyone traveling with pets to check current guidance before entering affected areas or transporting animals from them. Requirements can change as officials respond to new detections, so pet owners and rescue organizations should consult current USDA guidance and the relevant state animal health authorities rather than relying on older reports about travel rules. Nevada residents do not need to panic, but awareness matters. If you travel with your dog, keep an eye on any wounds, particularly after time outdoors, and contact a veterinarian if you notice unusual changes or signs of possible infestation. ## Signs to Watch for in Dogs and Other Animals USDA recommends that animal owners in affected areas inspect their animals daily for signs that could indicate screwworm infestation, including: - Draining or enlarging wounds. - Maggots or egg masses in or around a wound. - Unusual discomfort, irritability or sensitivity. - Lesions around the ears, nose, genital area or other body openings. These signs do not automatically mean an animal has screwworm, but they warrant prompt veterinary attention, particularly in areas where the pest has been detected. Do not attempt to treat a suspected infestation on your own. Contact a veterinarian or animal health official immediately and follow their instructions. Veterinarians and animal owners who suspect a case should report it promptly to the appropriate state animal health official or USDA APHIS. Early detection is important because larvae can cause severe tissue damage as an infestation progresses. ## Where to Find Current Information USDA is updating its confirmed-case dashboard as the situation develops. Pet owners, veterinarians and rescue organizations can check [USDA’s confirmed U.S. case dashboard](https://www.aphis.usda.gov/animals/animal-health/livestock-and-poultry-disease/current-status/us-confirmed-cases-new-world) and visit [Screwworm.gov](https://www.screwworm.gov/) for current response information. The agency’s full announcement about the Arizona case is available through [USDA APHIS](https://www.aphis.usda.gov/news/agency-announcements/usda-confirms-new-world-screwworm-arizona). The [CDC’s New World screwworm situation summary](https://www.cdc.gov/new-world-screwworm/situation-summary/index.html) provides additional information about risks to people and animals and recommended precautions. For Nevada’s dog owners, the takeaway is straightforward: the Arizona detection does not mean an outbreak is occurring in Nevada, but it underscores why checking animals for unusual wounds, seeking veterinary care quickly and verifying current travel guidance are important as the situation continues to develop.