To be physically, mentally and emotionally healthy, we all need contact with living things. Research into the bond between humans and animals reveals that something as simple as having a cat or dog as a pet, can protect us from numerous health problems including heart disease, cancer and depression.

Dr Edward T. Creagan, a cancer specialist at the Mayo Clinic deals on a daily basis with patients suffering from cancer induced stress and depression. He wrote in "Bottom Line Personal" July 2004:

"Social Connectedness, including the unconditional love of a pet, can protect against cancer. I often write a "pet prescription" for my patients. My three legged Golden Retriever gives us the best medicine of all."

Before I retired, I suffered from job related stress. When I returned home after a stressful day, my Cocker Spaniel "Chloe" was waiting for me at the door, tail wagging and ready for a play and a walk. Not only was the mutual affection and exercise good for both of us, it also released "feel good" hormones or endorphins that calm the body and help release tension. Simply stroking a cat or dog, or just being with them, can reduce and undo the stress generated by a busy day.

My situation was of course not unique, as all pet owners will testify. Dr Bernie Siegel, founder of "Exceptional Cancer Patients" recently discussed the effects of pets on heart attack victims in Australia. His research revealed that after one year, 6% of patients who owned a dog had died, compared with a 25% mortality rate in those who did not own a dog.

Dr Siegel has seen firsthand the extraordinary effects pets can have on our health and wellbeing. He has noted a positive change in body chemistry when pets are around. Levels of the stress hormone cortisol go down, immune function improves and serotonin levels increase. These are the same hormones that are elevated in a woman after giving birth, promoting bonding with her new baby.

But what causes these chemical changes?

Dr Siegel believes it is the unconditional acceptance and connection that animals consistently provide. They can also be incredibly intuitive. Often if a person is sick in bed, a dog will come and sit beside him/her. If that person was just taking a nap, the dog may not show the same level of concern.

"Animals respond to feelings, to what is really going on with their owners."

Dr Karen Allen is a research scientist at the School of Public Health, University of New York, Buffalo. Her work focuses on the therapeutic effects of pets in healing, depression and stress reduction. Her studies included the effects of having your best friend, spouse or pet present in stressful situations.

In one study, Dr Allen looked at women performing mental arithmetic problems alone, then with their best female friends present and finally, with their dogs present. With the friends present, the subjects experienced large increases in blood pressure {compared to when they worked alone}.However, when the dogs were present, insignificant increases, or none at all, occurred in blood pressure.

Her studies revealed, in both active and passive coping trials, participants experienced dramatic stress responses in the presence of another person, versus only slight increases in blood pressure in the presence of a pet. The consistent results led Dr Allen to conclude that pets clearly are a preferred source of social support. They are non judgmental, we don't have to impress them and they accept us for what we are.

Dr Siegel sums up the importance of pets in our lives. "Animals have an incredible ability to be completely there and completely devoted. How many of us can say that we are totally devoted to someone else's wellbeing? Animals are, and we respond positively to that."