This book explores the potential applications of animal stem cells in veterinary medicine. It begins with an overview of stem cells and their application in treating various animal diseases, including mastitis. In turn, the book discusses the challenges of using stem cells in regenerative medicine and emphasizes the importance of understanding the action of stem cells and preclinical evidence for ensuring safety and therapeutic efficacy. It also presents methods for the identification, characterization, and quantification of stem cells. Further, it discusses the therapeutic applications of different stem cells, including milk-derived, testicular, and mesenchymal stem cells in veterinary medicine. Lastly, it discusses strategies for and therapeutic applications of genome editing by CRISPER/Cas9 in mammary stem cells. As such, the book offers a valuable resource for students and scientists working in the veterinary sciences and veterinarians.