This book describes the animal health drug development process and compares and contrasts the veterinary and human processes. Such an approach can clarify some of the concepts about the pharmaceutical development and registration process as it relates animal health industry. The book addresses the processes, strategies, challenges, and coordination necessary to develop an Investigational New Animal Drug (INAD) which will have the best likelihood not only of being approved by regulatory agencies, but for candidate drugs which would have the best opportunity in demonstrating desirable efficacy and safety in the target animal population. A few chapters include relevant overviews of appropriate regulatory guidance, requirements, and expectations. This book also provides sources of initial information, pointing the reader to the appropriate agency and location of guidance documents.