Welcome to this emergency episode of Cattlemen & Veterinarians: A Partnership in Bovine Health. Just ahead, hosts Kaid Panek and Dr. Shynia Peterman provide a timely update on the New World Screwworm following its confirmed re-emergence in the United States. Dr. Peterman reports four confirmed cases as of Monday, June 8: three in calves in Texas and one in a dog in New Mexico, noting that all warm-blooded animals, including livestock, wildlife, and pets are susceptible. 

Dr. Peterman explains that the New World Screwworm is actually a fly whose adult females lay 200–300 eggs in wounds or mucous membranes. The eggs hatch within 12–24 hours, and the larvae burrow into living tissue in a screw-like fashion, causing severe tissue damage, pain, and potentially death if untreated. After about a week on the host, larvae drop to the ground to pupate in soil for one to 54 days, depending on temperature and humidity, before emerging as adult flies and continuing the cycle.

Producers are urged to observe livestock, horses, pets, and local wildlife daily. Warning signs include irritation, excessive head shaking, foul odor of decaying flesh, bloody or abnormal discharges, non-healing or enlarging wounds, visible eggs, or larvae in tissue. Any suspicious case should trigger immediate contact with a veterinarian, followed by rapid notification of state and federal animal health officials, as this is a reportable condition.

Dr. Peterman emphasizes thoughtful management around procedures that create wounds, such as branding, castration, dehorning, ear tagging, and calving assistance, especially in at-risk regions. She notes conditional approvals for products such as Dectomax CA-1 and Exalt Cattle CA-1, along with other emergency-use therapeutics listed on the FDA website, and stresses strategic use to prevent resistance.

On the regulatory front, USDA and the Texas Animal Health Commission have established 20-kilometer infested and buffer zones, imposed movement controls, and deployed millions of sterile male flies via air and ground release. Monitoring of wildlife and fly populations is ongoing, aided by fluorescent dye markers on sterile males.

The episode closes with reassurance that the New World Screwworm has been successfully eradicated before. The key messages are to avoid panic, remain vigilant, report promptly, and remember that this is an animal health and welfare issue rather than a food safety concern.

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