UC Davis Small Ruminant Research & Veterinary Extension

CLiK Extra is a new product that will be a great option to consider with your veterinarian as part of a NWS prevention plan. The meat withdrawal is 86 days after application, so it may be a good option for navels on newborns or young animals that benefit from management procedures, such as castration, tail docking, ear tagging, or disbudding, that create a wound. For adults that do not have a nearing harvest date this may be a good option to prevent NWS flystrike in wounds caused by birthing, shearing, or footrot control. Studies have shown that treated animals remain free of NWS for up to 18 days following application. The animals need to remain dry for up to an hour after application in order for it to have its expected efficacy. See the fact sheet from FDA for more information.

FDA Issues Emergency Use Authorization for Drug to Prevent New World Screwworm in Multiple Species, Including Sheep, Cattle, Goats, and Swine FDA today issued an Emergency Use Authorization (EUA) for CLiK Extra (dicyclanil topical suspension) wound spray for application on or around wounds for the prevention of New World screwworm (NWS) infestations (myiasis).

On June 5, 2026, USDA confirmed a second detection of New World screwworm (NWS) in a one-month-old calf in Zavala County, Texas, approximately 5.6 miles away from the first confirmed detection.

A USDA strike team is already on-site in Texas and is fully positioned to surge additional trained personnel as needed.

The FDA has issued emergency use authorizations for several NWS treatments for different species including sheep.

The National Veterinary Stockpile is actively procuring additional tools to treat and prevent NWS and has relocated NWS treatment supplies to Texas to better support affected producers in the infested zone.

If you or anyone you know needs access to these treatment supplies, they are now available and can be obtained by reaching out directly to the Texas Animal Health Commission (TAHC).

As part of the established NWS eradication strategy, USDA began releasing sterile flies over the area on June 4. These missions will disperse 2 million sterile screwworms twice a week to disrupt the pest’s lifecycle. In addition to aerial releases, USDA is shipping another 4 million sterile flies per week to Texas to be deployed using 24 ground release chambers.

USDA and TAHC remain in unified incident command and are maintaining a 20‑km infested zone with quarantines, movement controls, and heightened surveillance around the initial detection and establishing a new 20-km infested zone around the latest detection.

Anyone who suspects a screwworm infestation should immediately contact their veterinarian, state animal health official, or USDA.

The U.S. food supply remains safe. Screwworms do not infest meat, fruits, vegetables, or other food products.

More information about New World screwworm is available at Screwworm.gov.

For reliable information about New World Screwworm go to screwworm.gov and for California specific resources go to https://www.cdfa.ca.gov/ahfss/Animal_Health/screwworm/

AUSTIN, TX- On June 3, 2026, the Texas Animal Health Commission (TAHC) received confirmation of a detection of New World screwworm (NWS) in Zavala County, Texas. A sample collected from a three-week-old calf with an umbilical lesion was identified and confirmed as NWS by the National Veterinary Services Laboratory (NVSL) in Ames, Iowa. There are currently no further confirmed detections in animals in Texas.

Read the full press release here: https://bit.ly/6-3-26NWS

Hopland REC and UCCE are hosting another Virtual Fencing for Livestock Workshop on Friday, May 8.

Topics will include:
Targeted Grazing for Fire and W**d Control
Virtual Fence for Sheep
Leveraging NRCS Funding

Representatives from virtual fencing companies will also be there.

If you’re a dairy goat producer please consider taking this short survey. The results of this effort will help us understand current practices for internal and external parasite control as we prepare for future education events and recommendations for treatment and prevention of future pests such as New World Screwworm. https://shorturl.at/vjFjc