The series "Virus Infections of Vertebrates" is intended to supplement the plethora of monographs devoted to individual viruses. It was the editors' aim to present a "zoocentric" approach instead of the "virocentric" course most authors follow. This sixth volume in the series provides an up-to-date overview of the main viruses affecting equines. Its approach is pragmatic, with an emphasis on essential and useful facts rather than on detail of disease history or molecular data. The organization of the chapters is strictly hierarchical and follows virus taxonomy. At the beginning of each chapter, a short family description discussing infections caused by viruses in this family is given. The chapters have been written either in an epic style, without subdivisions (when only few data were available) or in subdivisions dedicated to virus properties (physical and chemical characteristics, antigenic properties and cultivation), epizootiology, pathogenesis, disease signs, pathology (gross lesions and histopathology), immune reaction, laboratory diagnosis, prophylaxis and control. Extensive literature references have been provided for further study.