This book, which is the first volume of the book series-Livestock Diseases and Management, summarizes the prominence and implications of the emerging and transboundary animal viruses. Although the livestock plays an important role in the economy of many countries, the emerging and transboundary animal viral diseases possess a serious risk to the animal-agriculture sector and food security globally. The book describes the precise and up-to-date information on animal viral diseases which have emerged in the recent past or are re-emerging due to various environmental factors and those which are not bounded in restricted national boundaries and attained the transboundary status. The chapters summarize the recent advancements in the molecular state-of-art tools towards the development of diagnostics, prophylactics, and therapeutics of these viruses. It also explicitly describes the challenges imposed by the emerging and transboundary viral infections and our preparedness to counter them.