Merck and Sanofi-Aventis have terminated their agreement to form a new animal health joint venture by combining their animal health businesses Intervet/Schering-Plough and Merial. As a result, both companies will maintain separate animal health businesses. The companies are terminating their agreement because of the increasing complexity of implementing the proposed transaction, in terms of the anticipated divestitures and the time it would take for the worldwide regulatory review process. M...