In ancient Egypt the dog was sacred to the god Anubis, protector of medicine. On his return to Ithaca, Odysseus was recognised only by his dog Argos. Many Sumerian deities were accompanied by animals in the treatment of illness. Asclepius, the Greek god of medicine, made use of dogs and snakes. The "curative power" of animals is neatly summed up by the well-known French proverb "Langue de chien, serte de medicine" (The tongue of a dog serves as medicine).

The first documented study of the scientific use of animals for therapeutic purposes dates back to 1792. The noted English psychologist William Tuke experimented, at a psychiatric hospital, with treatments that were less "brutish" and more "humane", using farmyard animals to help patients regain self-control.

In 1867, in Germany, where natural therapies have always enjoyed considerable development, a hospital was founded in which certain animals were used in the treatment of epilepsy.

In 1875, a French physician, Chessigne, prescribed horse riding to patients with neurological problems for the first time.

In 1919, in the United States and France, dogs were used for the first time to treat depression and schizophrenia caused by the First World War.

In 1942, the American Red Cross carried out the first attempt at the New York Military Hospital to rehabilitate severely wounded soldiers suffering from serious emotional disturbances, using pigs, horses and poultry.

In 1953, Boris Levinson, a psychotherapist, discovered the positive effect that an animal could have on a child displaying autistic behaviours. In the 1960s, Boris Levinson laid the scientific foundations for the birth of the first true animal therapy and the term "pet therapy" was used for the first time.

In 1970, in the United States, a psychiatric hospital adopted the first dog, named Skeezer, as an aid for children, achieving truly encouraging results. In those same years, the first ethological studies on primates also began.

In 1975, the married couple Samuel and Elisabeth Corson, two American psychiatrists, adopted the theories developed by Levinson to treat adults with mental disorders. The first pet therapy programmes in prisons and criminal asylums also began. Mugford and M'Comisky applied pet therapy to elderly patients.

In 1981, the Delta Society was established, an association dedicated to studying human-animal interaction.

In 1983, the Canadian Institute of Zootherapy was founded with the aim of studying and promoting therapy through animals.

In 1990, Tel Aviv University launched a project for the study of pet therapy.

In 1987, pet therapy arrived in Italy through an interdisciplinary conference, attended by internationally renowned experts, on the relationship between humans and animals. This was followed in 1991 by an international conference dedicated to the theme "Anthropology of a passion".

In 1992, a group of Australian researchers demonstrated that pet owners have lower blood pressure and significantly lower triglyceride and cholesterol levels than those who do not own animals.

In 2001, the Department of Geriatrics at Saint Louis University in the United States confirmed the full validity of pet therapy for many conditions affecting elderly people.