Globalization is not new. From the time of ancient migrations, human activities increasingly shaped the ecologies of health and disease around the world. When the peoples of the Western and Eastern Hemispheres encountered each other, the invading Europeans brought their domesticated animals, plants, and diseases with them. These demographic and ecological transformations ushered in a new era for animal healing and veterinary medicine. How were animal diseases circulating around the world due to exploration, colonialism, war, and trade? What was the impact of these diseases on human health and well-being, and on the projects of colonialism and state formation? The impacts of large-scale animal epidemics and pandemics enabled by the ecological exchanges of animals, parasites, and pathogens are analyzed. Further, this chapter highlights the development of physiology, pathology, and new disease causation models, while investigating how medical concepts, popular beliefs, and therapies were used in animal health care.

Veterinary medicine can be defined as the prevention, diagnosis, and treatment of animal health problems in the context of human–animal relationships. This broad definition is used in this book to include many types of animal healing throughout history. However, this "concise" history of veterinary medicine does not attempt to include all important topics in the history of animal healing. Instead, the history of animal healing and veterinary medicine is framed using a global and world history approach. Activities are included at the end of each chapter that encourage readers to explore the veterinary history of their own region and nation. Every chapter considers how animal healing interacted with tensions between the economic, military, and cultural value, status, and uses of domesticated animals. Who were the animal healers? What was their social status? How were they trained? What skills and knowledge did they have? How did people explain or theorize, and respond to, animal health problems in each place and time period?

In 2021 veterinary medicine faces traditional concerns and new realities. These include the need to ensure food animal and herd health in a world increasingly affected by emerging diseases and climate change. However, most Western veterinarians specialize in individual treatment of companion animals (pets), not herd health, and this is becoming more common globally. Veterinary leaders are concerned about this workforce imbalance, the challenges of critical animal owners and consumers, and sustainable food production. Many people have ethical concerns about technological developments such as the ability to genetically modify and clone organisms. Young veterinarians face educational debt, increasing competition, and high levels of stress. In response, veterinary education must include the "soft skills" and "support skills," such as how to communicate effectively, make ethical judgments, and manage stress. The veterinary profession, and its members, must be well informed, flexible, and able to change quickly to meet the challenges of animal owners’ expectations, controlling disease without harming ecosystems, and feeding the world’s people despite the inequalities built into the global animal economy. As mediators between humans and animals, veterinarians and other animal healers have both shaped and been shaped by the social, cultural, and economic roles of animals over time.

Veterinary education, training, and employment shifted to support military needs in wartime. Conflicts around the world, including World War I, relied on millions of horses, dogs, and food-producing animals to supply armies. Wartime disruptions, and the movement of so many animals, sparked outbreaks of diseases that challenged animal owners, healers, and veterinarians. The use of horsepower declined in industrialized areas, depriving veterinarians of their most important patients. Many turned instead to livestock and food production. National campaigns against bovine tuberculosis, brucellosis, and other zoonoses employed many veterinarians. Others worked on vaccines and therapeutics in biomedical research. With the outbreak of World War II, ethical questions troubled veterinarians who contributed to the development of biological weapons. Rebuilding the world’s food production systems after the war stimulated international veterinary cooperation and incorporated new tools, such as antibiotics. Veterinarians also helped make intensive animal production ("factory farming") possible by controlling diseases, while more and more vets in wealthier areas treated companion animals (pets).

Developments in international trade, colonialism, and conquest created the military needs (healthy army horses) and economic needs (controlling great animal plagues) that shaped the professionalization of modern veterinary medicine in Europe and beyond. This chapter analyzes how the circulation of veterinary knowledge was organized in the eighteenth and nineteenth centuries, amidst the challenges of animal disease outbreaks and battlefield injuries that had accompanied war and trade. It examines how modern veterinary schools emerged from European Enlightenment pragmatism and French physiocrat economics, and why and how this model of education spread around the world. State promotion and regulation of veterinary education and professionalization of veterinary practitioners increased, augmenting the traditional roles of herders and healers in many areas. Veterinarians educated in this formal European tradition slowly expanded their share of the market for veterinary services as their numbers and state-sponsored influence grew. The development and spread of the eighteenth-century European veterinary regime was a product of its time. It fulfilled crucial social, political, military, and cultural needs during subsequent decades of increasing industrialization and imperialism affecting the globe.

In the late twentieth century, the global human population grew dramatically. Global meat production more than doubled as industrial animal production rapidly accelerated. Mechanization, artificial insemination, growth promoters in feed, and disease control contributed to successful "factory farms," while smaller farmers adopted vaccines and antimicrobials. By 2000, 90 percent of the mammals living on earth were humans and their domesticated animals. Veterinarians became "herd health" managers and worked for governments around the world to carry out vaccination programs, provide medications and anthelminthics, and complete inspections and certifications. The OIE and WHO coordinated international campaigns against rinderpest, foot and mouth disease (FMD), and swine fever; but outbreaks of FMD resulted from disagreement over the value of vaccination versus testing. Prion diseases (scrapie and BSE) became major sociopolitical problems after people acquired a form of BSE from infected meat in Britain. Public concerns about food safety, antibiotic resistance, and animal welfare began to challenge intensive livestock production and veterinarians’ role, but most veterinarians in wealthy areas focused on companion animals. By 2000, racial and ethnic diversity in the veterinary workforce was slowly increasing, while the profession rapidly feminized after 1980 in most parts of the world. Responding to client demand, veterinary schools began offering courses in complementary and alternative veterinary medicine (CAVM).

This chapter highlights traditions of animal healing around the globe, from South American, to Islamic and Ottoman, to Ayurvedic, Chinese, and European. The domestication of elephants, horses, poultry, bovines, and other animals, supplied animal bodies for food, transport, power, and cultural status. Many societies incorporated animals into their sacred traditions and developed elaborate systems of knowledge about animals, including animal healing. Keeping animals close to or inside people’s houses effectively altered the environments of both. People and their domesticated animals shared microorganisms (which also co-evolved with them over time). A major problem with the closeness of human and domesticated animal populations was the spread and evolution of pathogens, forcing healers for both humans and animals to confront the challenges of emergent diseases. Early veterinary activities are analyzed, including professionalization, and linked to the more well-known histories of military animal healers and writings on animal anatomy and medicine by the 1500s.

The numbers of pets, availability of goods and services for them, and the veterinary profession’s attention to companion animal medicine are increasing (especially in Asia and Latin America). The concept of "anthropomorphism" (attributing human characteristics to animals) contributes to the idea that family pets are worthy of expensive care. Animal welfare activism expanded in Western societies and became politicized in Europe. These changes led to reductions in the use of laboratory animals and veterinarians’ increased attention to animal suffering. While traditional healing systems are often combined with Western veterinary medicine around the world, in some places the standard of animal care was based on that of human hospitals. Veterinarians adopted new technologies, including CT and MRI scanning and genetic testing. Personal computers, the internet, and mobile phones have revolutionized veterinary practice in some areas; this required veterinarians to learn new skills. In 2011–2012, veterinarians celebrated the World Veterinary Year, (250th anniversary of the first European veterinary school) and the eradication of rinderpest from the world (a triumph for veterinary international cooperation). Veterinarians have been major drivers of "One Health," the most recent effort to combine all aspects of health care for animals, the environment, and humans to address ecosystem destruction and prevent disease outbreaks.

In the early 1800s, animal owners and local healers provided most veterinary care, and indigenous healing methods thrived around the world. Colonialism, global trade networks, and other circulations of animals led to disease outbreaks (epizootics). Rinderpest, imported by Europeans, destroyed about 90 percent of all wild and domesticated bovines in sub-Saharan Africa, causing devastating famines. European-model veterinary schools continued to spread around the world. Their graduates worked to reduce competition by developing laws and regulations that forbade non-graduates from practicing animal healing. Veterinary leaders envisioned "scientific" veterinary medicine, using microscopes and other tools. By working to establish microbiology, comparative pathology, and "one medicine," veterinarians were important co-creators of modern medicine and public health as we know them today. Ideas about disease causation included the roles of the environment and insects in spreading disease; the contagium vivum; parasitism; toxins; and several germ theories. Some veterinarians treated companion (pet) animals, whose owners valued them for emotional reasons. Associations for the humane treatment of dogs and other animals were established. Pet owners increasingly expected scientifically trained veterinarians to provide the same services for pets that their owner could expect at a hospital for humans.