A dangerous parasite, the New World screwworm, has been detected in a cow in Mexico, leading the USDA to prohibit animal imports from Mexico. The parasite was found at a checkpoint in Chiapas, near the Guatemala border, marking its advancement from South and Central America into the U.S. The screwworm poses a significant threat to livestock and other warm-blooded animals by burrowing into flesh and causing severe damage. Originally eradicated from the U.S. in 1966, it continues to be endemic in certain regions. Authorities are working to implement pest monitoring and prevention measures, including the release of sterilized male flies to control the population. Animal owners are advised to keep wounds clean, covered, and treat with repellents to prevent infestations. Any signs of screwworm should be reported immediately.