http://www.drmartinwilliams.com/healingpets/healingpets.html

A study of some 6000 patients revealed that those with pets had lower blood pressure, a lower cholesterol level and, as a result, a diminished risk of heart attack. And American researchers have established that, even after a heart attack, pet owners are more likely than other coronary patients to be alive a year later.

pets can also help us by making us feel less lonely, by creating a feeling of being needed and by encouraging social contact with others interested in animals. They are also a stimulus for healthy exercise, keep us busy and make us feel safe.

For some people, animals can provide more consistent emotional support than humans. A Warwich University, England, study found that people who are poor at confiding in others, showing love or making friends were able to lavish affection on a pet.

In Britain, some prisons now encourage inmates to keep pets - caged birds, tropical fish, even cats. These can be a magical ingredient to bring about long-term changes in attitudes and behaviour, with prisoners often finding out for the first time what it's like to give and receive affection.