06/05/2026
By now, most of you have probably heard about the recent New World screwworm detection in South Texas. While this is certainly something producers should take seriously, there is no reason to panic. Early detection, good herd management, and a solid animal health program can significantly reduce the risk to your operation. USDA and Texas animal health officials are actively responding to the situation and encouraging producers to increase surveillance of their livestock.
New World screwworm flies are attracted to open wounds, where they lay eggs. The larvae then feed on living tissue, making regular herd observation critical.
Steps You Can Take to Protect Your Herd
1. Maintain a Consistent Parasite Control Program
Follow a strategic deworming program at least twice per year, or as recommended by your veterinarian.
Products such as Dectomax®, Ivomec®, and similar products can be part of an effective herd health program.
Work with your veterinarian to determine the best protocol for your operation.
2. Implement Fly Control Measures
Fly control is an important line of defense, especially during our extended fly season.
Consider using:
Fly sprays (rotate active ingredients to help prevent resistance)
Back rubbers
Dust bags
Fly tags
Feed-through fly control products where appropriate
3. Inspect Cattle Frequently
Check cattle more than once per week whenever possible.
Pay close attention to:
Open wounds
Branding sites
Castration sites
Dehorning sites
Navel areas on newborn calves
Ear tags and other injury locations
Watch for unusual swelling, drainage, foul odors, irritation, or the presence of maggots. These can be warning signs that require immediate attention.
4. Treat Wounds Promptly
Clean and monitor all wounds.
Follow your veterinarian's recommendations for wound care and fly prevention.
Animals with untreated wounds are at greater risk of attracting screwworm flies.
5. Contact Your Veterinarian Immediately if You Suspect a Problem
If you notice suspicious wounds, maggots, or other signs of infestation:
Contact your veterinarian immediately.
Follow all reporting and treatment recommendations.
Early intervention is critical for successful treatment and containment.
Additional Resources
USDA APHIS Screwworm Information: USDA New World Screwworm Resources
Federal Response & Current Status Updates: Screwworm.gov
The most important thing producers can do right now is remain vigilant. Regular cattle checks, good wound management, fly control, and a strong relationship with your veterinarian are the best tools available to protect your herd.
Learn how the U.S. Government prevents New World screwworm and what to know about risks, surveillance, sterile-fly control, travel, and more.
