This book presents a list of important animal diseases that occur in developing nations, and is written predominantly by experienced scientists from several developing countries. The origin of the main objective that was considered in the preparation of this book was to provide high-quality literature of international standards for veterinary students, practicing veterinarians, and veterinary diagnosticians in developing and underdeveloped countries but written by scientists/professors from these regions. This is of fundamental importance, since most books on infectious and parasitic diseases of domestic animals, used worldwide in universities and other institutions, are written predominantly by American and/or European-based authors/scientist and frequently reflects the American and/or European views of specific diseases, which does not always coincide with the manifestations of these diseases in developing countries. Consequently, this book offers an alternative view of important diseases of animals based on the experience of scientists from developing countries. It is our intention that this book serves as a complementary text for these specific diseases so that veterinary students and veterinarians from developing countries may easily identify these disease processes in domestic and/or wild animals.