Animal and Plant Health Inspection Service APHIS

Federal efforts to stop livestock disease date to the Bureau of Animal Industry of 1884, created to fight cattle diseases that threatened exports. The Animal and Plant Health Inspection Service was formed in 1972 by pulling inspection and quarantine work out of the Agricultural Research Service. It operates under the Plant Protection Act of 2000 and the Animal Health Protection Act of 2002 and is led by an Administrator who reports to the Under Secretary for Marketing and Regulatory Programs.

APHIS inspects imported plants and animals, sets quarantines, tracks and eradicates outbreaks of diseases such as avian influenza and foot-and-mouth disease, and fights invasive pests from the boll weevil to the Mediterranean fruit fly. It regulates genetically engineered organisms that could pose plant pest risks, enforces the Animal Welfare Act at research labs, zoos, and commercial breeders, and runs Wildlife Services, which manages conflicts between wildlife and agriculture, including predator control that has long drawn criticism from animal advocates.

Since 2022 a highly pathogenic H5N1 bird flu has forced the culling of well over a hundred million poultry and pushed egg prices to records, and in March 2024 it was confirmed in dairy cattle for the first time. In 2025 the agency suspended imports of live cattle from Mexico to block the New World screwworm, a flesh-eating parasite moving north, and expanded production of sterile flies to stop it. The pest was detected in Texas and New Mexico in mid-2026, with more than 30 cases reported, and in August 2026 USDA began a phased reopening of the border to Mexican cattle. Supporters of aggressive measures cite the cost of an outbreak in the U.S. herd, while ranchers and trading partners have pressed for faster reopening.