Screwworm Outbreak Warning: 5 Critical Facts That Could Save Your Livestock
- This parasitic nightmare is back: The New World screwworm (Cochliomyia hominivorax) is a flesh-eating fly larva that can burrow into open wounds of warm-blooded animals, including humans. An outbreak in the Florida Keys and parts of Central America has triggered emergency quarantines and travel restrictions.
- It spreads like wildfire through infected animals: Screwworms are not maggots. Unlike common maggots that eat dead tissue, these larvae attack living flesh, causing severe infections and death if untreated. A single infested wound can release thousands of eggs to contaminate other animals in the herd.
- Your animals are showing creepy symptoms early: Watch for depression, loss of appetite, a foul smell from wounds, and visible tiny, cream-colored larvae. Check livestock ears, nostrils, and navels daily; early detection is the only chance for survival.
- Treatment requires a swift, ugly process: You must physically remove every single screwworm from the wound (by hand or with tweezers), then apply a thick, larvicidal ointment. Any missed larvae can cause reinfestation. Immediate vet care is non-negotiable.
- The official weapon: a mass-release of sterile flies: The U.S. and Central American governments are deploying millions of sterile male screwworm flies from planes. This biological warfare method matings with females produce no offspring, crashing the population. Report any suspected case to the USDA immediately—failure to do so can lead to penalties and rapid spread across the region.