Ozone therapy has been reported to be effective in humans, but there was still small numbers of reports in veterinary medicine. Rectal insufflations (RI) of oxygen-ozone was effective as well as major ozone autohemotherapy (AHT), the procedure was easy to perform, painless, inexpensive and had no side effects. Subcutaneous (SC) injection of oxygen-ozone were also easy to perform for veterinarians. Ozone therapy were effective and may be used in conjunction with all conventional and natural treatments like humans. Ozone therapies were effective for dogs and cats. Animal patients receiving ozone therapy could maintain high quality of life.