Medical ozone

can be an important adjunctive treatment for maintaining health and function in the face of many disease syndromes, such as cancer, chronic inflammatory disease, and systemic infectious processes.  Ozone is widely used as a therapeutic modality in Europe, Asia and the Middle East.  Although highly controversial in the U.S., recently passed Alternative Therapy Legislation has made ozone therapy an option for human patients in some states: Alaska, Arizona, Colorado, Georgia, Minnesota, New York, New Jersey, North Carolina, Ohio, Oklahoma, Oregon, South Carolina, and Washington.

Medical ozone is administered in controlled doses, and is believed by its proponents to aid in normal physiologic anti-oxidant function.  In cancer treatment, ozone is thought to aid the body in mobilizing the immune system against hypoxic tumors.  The Wikopedia entry on Medical Ozone use presents both the supposed benefits and dangers of this modality:

http://en.wikipedia.org/wiki/Ozone_therapy

The delivery method used in companion animals, trans-rectal insufflation, is safe and minimally invasive.  Sick animals treated with ozone appear to feel better, and have an improved attitude as an immediate benefit.