1. New World Screwworm found in calf in the Valley [TX]
By: Mia Morales
ValleyCentral.com
July 29, 2026
HARLINGEN, Texas (ValleyCentral) - Starr County officials have confirmed its first screwworm case in the western area of Starr County.
Starr County Emergency Management spokesman Lenny Fuentes said the larvae was found in a baby calf.
According to a social media post, Starr County officials say they are working closely with the Texas Animal Health Commission and other local and state partners to contain the spread of the parasitic fly and protect livestock, wildlife, pets, and other animals.
Full text: https://www.valleycentral.com/news/local-news/new-world-screwworm-found-in-calf-in-the-valley/
2. Utah reports H5N1 in poultry, cattle
By Stephanie Soucheray, MA
CIDRAP News
July 16, 2026
In US news, the US Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) reported for the second week in a row an egg farm H5N1 outbreak in Cache County, Utah, affecting 275,100 birds. In the past 30 days, 1.49 million birds have been hit with H5N1 in the United States.
APHIS also noted several new detections of avian flu in cattle in Utah and Idaho, with each state reporting four confirmed cases this week. Twenty-six cattle in the past 30 days have been confirmed to be infected with H5N1, raising the year's total to 81 cases.
3. Veterinarians key part of response to screwworm [edited]
Experts describe what practitioners need to know and what's being done to mitigate the pest
By Malinda Larkin
AVMA News
July 16, 2026
Few U.S. veterinarians have encountered New World screwworm (NWS) in their lifetime, so it's not just the public that needs more education on what the parasite looks like, how to treat myasis, and how to prevent the pest's spread.
Since June 3, when the first NWS detection associated with the current outbreak was reported on the U.S. mainland, 37 cases have been detected in two states, 17 of which are active cases, according to the U.S. Department of Agriculture (USDA). Although NWS has not been established in the United States since the 1960s, sporadic cases have occurred during the intervening decades, including in the Florida Keys.
Screwworm refers to the larval (maggot) stage of the NWS fly, which feeds on living tissue. Using its sharp, hook-like mouthparts, the larvae borrow deeply into wounds or body orifices, creating severe wounds that can be fatal if not promptly identified and treated. "A quarter-inch wound on Day 1 can become a five-inch wound by Day 2," she said. "These are deep wounds that can penetrate into body cavities."
The NWS fly has a "frighteningly efficient" 21-day life cycle, Dr. Kelliher said. An adult female fly can lay up to 3,000 eggs in a wound, surgical site, or orifice during her 10- to 30-day lifespan. The eggs hatch into larvae within 12 to 24 hours, then feed on living flesh for five to seven days before dropping to the ground, where they burrow and pupate. Adult flies emerge six to eight days later and repeat the cycle.
NWS flies are attracted to the scent of blood, making animals that have newly given birth or newborns with an unprotected umbilicus a beacon. The same goes for animals that have recently undergone surgical or management procedures, including castration, tail docking, dehorning, or ear tagging. Even something as small as a tick bite can draw egg-laying female NWS flies, Dr. Kelliher said.
Full text: https://www.avma.org/news/veterinarians-key-part-response-screwworm
Border leaders call for coordinated New World screwworm response
Miller urges Trump Administration and USDA to continue accelerating sterile fly production, strengthen surveillance along the southern border.
National Hog Farmer
July 17, 2026
Texas Agriculture Commissioner Sid Miller joined federal, state and industry leaders in New Mexico for a New World Screwworm Summit, calling for immediate, coordinated action to stop the pest before it further threatens America's livestock industry, wildlife, pets and economy. The summit brought together officials from across the region, both in the United States and Mexico, to discuss surveillance, eradication strategies, cross-border coordination and the urgent to need use every proven tool to eliminate the NWS threat. The event took place at the New Mexico Border Authority facility in Santa Teresa, which is home to the most modern livestock processing facility on the U.S./Mexico border, a critically important link between the agricultural economies of the United States and Mexico.
"The New World screwworm doesn't care where a state line or international border is," Commissioner Miller said. "This is a fight for every rancher, every producer, and every American who depends on a safe and secure food supply. We cannot afford bureaucracy or half measures when our food security and billions of dollars are on the line on both sides of the border."
Commissioner Miller reiterated his call for the United States to fully utilize the proven Screwworm Adult Suppression System, the USDA-developed program that successfully eradicated New World screwworm from the United States decades ago. The summit participants agreed to a new charter agreement committing all parties to increased communication, better coordination and a commitment to using every proven tool to combat the New World screwworm.
Maine restricts animal entry after invasive fly detected in U.S.
WABI.tv
July 18, 2026
AUGUSTA, Maine (WABI) - The Maine Department of Agriculture, Conservation, and Forestry is imposing new movement restrictions and entry requirements for animals coming into the state following the detection of New World Screwworm in the United States.
Under the new rules, any infested animal or suspected infested animal will not be allowed into Maine. Any animal originally from an area where NWS quarantine procedures are in place will not be allowed in until the quarantine is complete. Any healthy animal not under quarantine from an infested zone will be placed under surveillance.
Full text: https://www.wabi.tv/2026/07/18/maine-restricts-animal-entry-after-invasive-fly-detected-us/
5. Canada proposes easing BSE feed rules to align with US
Some cattle tissues could be permitted in pet food and fertiliser
By: Global Ag Media
The Cattle Site
July 16, 2026
The Canadian Food Inspection Agency has proposed regulatory amendments to better align Canada's Enhanced Feed Ban with US requirements, reducing restrictions on certain cattle tissues while maintaining safeguards against bovine spongiform encephalopathy, agriculture minister Heath MacDonald announced July 13.
The Enhanced Feed Ban, introduced in 2007, prohibits most mammalian proteins from ruminant feed. The proposed changes would allow a subset of lower-risk specified risk material - cattle tissues capable of transmitting BSE if the animal is diseased - to be used in non-ruminant feed, fertiliser and pet food. All specified risk material would remain prohibited in food and ruminant feed.
The CFIA said federal risk assessments by the agency, Health Canada and the Public Health Agency of Canada confirm the changes would not increase BSE risk provided existing safeguards remain in place. Canada was recognised by the World Organisation for Animal Health as having negligible BSE risk status in 2021, reaffirmed under updated 2023 standards.
The agency said the amendments would reduce costs and unnecessary waste for industry while supporting the competitiveness of Canada's cattle and processing sectors. Stakeholders are invited to submit comments by September 9, 2026.
Source: https://www.thecattlesite.com/news/canada-proposes-easing-bse-feed-rules-to-align-with-us
6. Unvaccinated Arizona Horse Tests Positive for WNV
EDCC Health Watch
TheHorse.com
July 16, 2026
One horse in Maricopa County, Arizona, recently tested positive for West Nile virus (WNV). The horse is unvaccinated.
Full text: https://thehorse.com/1146044/unvaccinated-arizona-horse-tests-positive-for-wnv/