Merck & Co., Inc. is a global health care company. The Company offers health solutions through its prescription medicines, vaccines, biologic therapies and animal health products. It operates through two segments: Pharmaceutical and Animal Health. The Company's Pharmaceutical segment includes human health pharmaceutical and vaccine products. Its human health pharmaceutical products consist of therapeutic and preventive agents, generally sold by prescription, for the treatment of human disorders. The Company sells these human health pharmaceutical products primarily to drug wholesalers and retailers, hospitals, government agencies and managed health care providers such as health maintenance organizations. The Animal Health segment develops, manufactures and markets a wide 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.