The second volume of this Review principally looks at viral diseases, but also considers bacterial diseases and, finally, parasitic diseases. The description of each disease has been updated in accordance with the most recent scientific research, focusing on epidemiology and control. Particular emphasis is placed on emerging diseases (such as infection with the Schmallenberg virus) and diseases that have a zoonotic component (such as West Nile fever). Diseases that have experienced a recent geographic expansion (bluetongue, fever due to the Chikungunya virus) are also discussed. In total, twenty-nine diseases are covered.