Animals have played a critical role in human lives for centuries. Initially the role of animals would have been primarily for transportation, agricultural uses, or food but as humans became less dependent on animals for these needs, they continued to keep animals in their lives. Although such animals are most commonly referred to as pets, the change in role has led to descriptive terms including companion animals and the human-animal bond.

Despite the cost, work, and inconveniences of pet ownership, the number of pet animals has been steadily increasing. According to the American Pet Products Association (2018), the National Pet Owners Survey of 20172018 found that approximately 85 million U.S. households (68%) reported owning a dog, cat, or other companion animal. The largest percentage of households reported owning one or more dogs, followed by cats, birds, and fish. The U.S. Pet Ownership and Demographics Sourcebook, published by the American Veterinary Medical Association (2012), reports that approximately 70 million dogs and 74 million cats are owned by families in the United States.

Although the benefits of companion animals, or pets, have been reported to include physical, mental, and psychosocial aspects, there are risks that need to be considered. Potential risks of contact with animals include bites, allergies, or zoonosis. The term zoonosis has been defined and used in the medical community for years. According to Merriam-Webster, zoonosis is an "infection or disease that is transmissible from animals to human under natural conditions." The newer term "zooeyia," refers to the benefits of human and animal interactions. Although zooeyia has not been entered in Merriam-Webster, the word has appeared in literature since at least 2011 and has been defined in the Merck Veterinary Manual. Donald Noah, DVM, and Stephanie Ostrowski, DVM, (2018) explained:

Zooeyia is defined as "the positive inverse of zoonosis" and represents the innumerable benefits that stem from human interaction with animals. Too often, that interaction focuses on negative issues such as disease and injury rather than on the positive contributions to our physical, mental, and social well-being. These contributions are manifested at both the individual and community levels. Documented individual benefits of interaction with animals include increased physical activity, smoking cessation, hypertension control, reduced anxiety, and treatment of post-traumatic stress disorder. Interaction with domestic animals contributes at the community level by facilitating social interaction, promoting a sense of safety, enhancing the "give and take" communication between neighbors and fellow pet owners, and perhaps even lowering health care costs.

The benefits of dog ownership have become an expectation. Powell et al. (2018), in a study of over 3,000 prospective adopters of a dog, found that the future dog owners reported that they expected to increase their exercise, happiness, and companionship. The research participants stated that they knew there would be responsibilities in caring and training their dog, but also acknowledged that they anticipated decreased stress and loneliness.

Many pet owners would note that it is so obvious that pets make their lives better that it is not necessary to document that...