Merck & Co., Inc. is a global health care company that delivers health solutions through its prescription medicines, including biologic therapies, vaccines and animal health products. The Company's segments include Pharmaceutical and Animal Health. Pharmaceutical segment includes human health pharmaceutical and vaccine products. The Company sells its human health pharmaceutical products primarily to drug wholesalers and retailers, hospitals, government agencies and managed health care providers. It sells its human health vaccines primarily to physicians, wholesalers, distributors and government entities. Animal Health segment discovers, develops, manufactures and markets a range of veterinary pharmaceutical and vaccine products, as well as health management solutions and services, for the prevention, treatment and control of disease in all major livestock and companion animal species. It sells its products to veterinarians, distributors, animal producers, farmers and pet owners.