The incredible news from a US university is that my pet actually helps me stay healthy. Researchers believe that stroking a dog triggers hormone release in the human brain to fight depression and stress-related sickness.

Feel-good chemicals such as serotonin, prolactin and oxytocin start to flow more freely within seconds of contact with a furry friend - and the stress-out hormone cortisol fades away.

Dogs have been man's companion since the Stone Age, and I have always felt instinctively that I need a pet to keep a smile on my face and help me stay positive. I've owned a dog ever since my father presented me with a puppy in Tel Aviv, when I was not yet ten. I made sure my own kids had pets too. Dr Rebecca Johnson, the professor leading the study at the Missouri University College of Veterinary Medicine, said: "Could a dog help mediate serotonin levels in order to help depressed patients? By showing how interacting with pets actually works in the body to help people, we can help animal-assisted therapy become a mainsteam medically-accepted intervention that would be prescribed to patients and, in the long run, be reimbursed by insurance companies."

American academic language resembles English only faintly, but I think what she's saying is that if people feel better when they cuddle their pet, then doctors ought to take this therapy seriously - and insurance companies should foot the bill.

Don't laugh - insurers could soon be offering a discount to pet-owners, just as they now do to non-smokers. My own belief is that hormones are only part of the medical story. The real benefit to owning any pet, from a budgie to a boa constrictor, is the unconditional love that flows between you and your animal friend. Dogs have never let me down and they always forgive me.

That's the most valuable lesson in loyalty any human could learn.