Texas agricultural officials issue emergency quarantines across 21 counties for screwworm parasite

Federal and state agricultural officials have confirmed that the number of New World screwworm cases in the United States has reached 26, as Texas authorities issue a wave of emergency quarantine orders to contain the flesh-eating parasite's expansion into Deep South Texas.

New World Screwworm update

According to official records, 25 of the confirmed cases are concentrated across Texas, with one domestic animal case identified in Lea County, New Mexico.

The latest wave of detections has prompted Texas Animal Health Commission (TAHC) Executive Director Dr. Lewis R. Dinges to sign multiple emergency orders expanding strict animal movement restrictions.

Outbreak Reaches the South Texas Border

In a major geographic expansion, Dr. Dinges signed an emergency order on June 26, 2026, establishing Infested Zone 10. This new zone comes after the aggressive parasite was detected on June 25 in a bovine located in Jim Hogg County.

View the zone map

The resulting quarantine imposes strict, immediate animal movement restrictions across designated portions of three border-region counties:

• Jim Hogg
• Starr
• Zapata

Quarantines in West and Central Texas

The parasite has also shown resilience in previously identified outbreak zones, forcing state regulators to broaden existing boundaries due to new animal infections:

Infested Zone 07.A: Declared on June 25, 2026, this order replaces previous restrictions after the screwworm was detected in sheep outside the original containment borders in Crockett County on June 24. The expanded zone restricts livestock movement in parts of Crockett, Schleicher, Sutton, and Val Verde counties.

Infested Zone 04.C: Issued on June 26, 2026, this represents the third modification of containment zones in the area. It follows a new detection in an Edwards County sheep on June 25, impacting parts of Edwards, Sutton, and Val Verde counties.

Full List of Restricted Texas Counties

State agricultural officials emphasize that localized quarantines and strict movement restrictions are now actively enforced across parts of 21 Texas counties:

• Bandera
• Coke
• Crockett
• Edwards
• Gillespie
• Jim Hogg
• Kerr
• Kimble
• La Salle
• Medina
• Pecos
• Schleicher
• Starr
• Sutton
• Terrell
• Tom Green
• Uvalde
• Val Verde
• Webb
• Zapata
• Zavala

Under the active TAHC emergency mandates, no warm-blooded animals located within these designated infested zones can be moved outside the quarantine borders without prior official authorization. Hides, carcasses, and animal parts capable of hosting the larvae are also barred from transport until they are physically inspected, treated, and cleared by a commission representative. Unauthorized movement remains subject to administrative penalties and criminal prosecution.

Severe Agricultural Threat

The New World screwworm (Cochliomyia hominivorax) is considered a severe threat to livestock, exotic livestock, and wildlife. The parasitic fly targets open wounds—even minor abrasions or tick bites—to deposit eggs. The hatched larvae burrow into live tissue, causing a painful condition known as myiasis, which can be fatal if untreated.

Governor Greg Abbott’s statewide disaster proclamation, originally issued on January 29, 2026, and updated on June 5, remains actively in effect to facilitate rapid resource deployment through the State Emergency Operations Center.

Livestock and pet owners are urged to inspect animals daily. Suspected cases must be reported immediately to the TAHC at 512-719-0700.

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