Zoetis sells anti-infectives, vaccines, parasiticides, diagnostics, and other health products for animals. The firm earns slightly less than half of total revenue from production animals (cattle, pigs, poultry, and so on), and more than half from companion animal (dogs, horses, cats) products make up the other half. Its U.S. business is heavily skewed toward companion animals, while its international business is slightly skewed toward production animals. The firm has the largest market share in the industry and was previously Pfizer's animal health unit.