Animal shelter is a place where stray, lost, abandoned or surrendered animals such as dogs and cats are housed. The main objective of animal shelters is to reunite pets with their old or new owners, and shelter those in need. A major factor that affects the behavior of shelter animals is their interaction with many unfamiliar people. They suffer from a lack of predictability and control in their daily lives. Some animals enter shelters with behavioral problems such as aggression, lack of sociability and fearfulness. Contrarily, some animals develop problematic behaviors as a result of their shelter experiences. Shelter veterinarians are the doctors that look after the well-being of shelter animals. They are responsible for treating various medical conditions, maintaining herd health, and providing high-quality medical care to these animals. This book presents an account of available research on the behavior of shelter animals. It will serve as a valuable source of reference for students and professionals of veterinary science.