Sheep, a ruminant mammal, is of the genus Ovis. The sheep are the species of livestock that play a salient role in the global agricultural economy. Sheep farming is rewarding in several ways including production of milk, meat, and wool. However, sheep are prone to various infectious and non-infectious diseases. The illness of sheep affects the import and export of livestock. There are some diseases that are contagious and can be transmitted to humans. Such diseases are termed as zoonotic diseases or zoonosis. Insulating sheep from diseases is crucial for the health and wellbeing of the flock, as well as for the earnings in the business. This book details few diseases affecting sheep, and some strategies to improve welfare of the herd.