The Animal and Plant Health Inspection Service (APHIS) is an agency of the United States Department of Agriculture (USDA) based in Riverdale, Maryland responsible for protecting animal health, animal welfare, and plant health. APHIS is the lead agency for collaboration with other agencies to protect U.S. agriculture from invasive pests and diseases. APHIS is the National Plant Protection Authority for the U.S. government, and the agency's head of veterinary services is Chief Veterinary Officer of the United States.