Merck, Sanofi merge animal medicine units

Two of the world’s biggest pharmaceutical companies said Tuesday they are uniting their animal health businesses in a deal to become the top dog in the veterinary industry.

Merck & Co. and France’s Sanofi-Aventis SA said they’ll jointly own the combined business, which will have a share of about 29 percent in the $19 billion-a-year global market for medicines for pets and livestock. That’s well ahead of the current leader, Pfizer Inc.’s Fort Dodge unit, which has about 20 percent of the market.