If you want to live a healthier life get a dog, research suggests.
Dogs can provide companionship
The companionship offered by many pets is thought to be good for you, but the benefits of owning a dog outstrip those of cat owners, the study says.
A psychologist from Queen's University, Belfast, said dog owners tended to have lower blood pressure and cholesterol.
Writing in the British Journal of Health Psychology, she says that regular "walkies" may partly explain the difference.
Dr Deborah Wells reviewed dozens of earlier research papers which looked at the health benefits of pet ownership.
She confirmed that pet owners tended in general to be healthier than the average member of the population.
However, her research suggested that dog ownership produced more positive influence than cat ownership.
As well as lower blood pressure and cholesterol, she said dog-owners suffered fewer minor ailments and serious medical problems.
There was also the suggestion that dogs could aid recovery from serious illnesses such as heart attacks, and act as 'early warning' to detect an approaching epileptic seizure.
Dr Wells said the precise reason for the benefits was not totally clear.
"It is possible that dogs can directly promote our well-being by buffering us from stress, one of the major risk factors associated with ill-health.
"The ownership of a dog can also lead to increases in physical activity and facilitate the development of social contacts, which may enhance both physiological and psychological human health in a more indirect manner."
Dr June McNicholas, a health psychologist who has specialised on research into the health effects of pet ownership said that an important reason for the improved health of dog-owners was not just the exercise received while taking it for walks, but the opportunity for social contact with other dog-owners.
She said: "For older people, an animal can fulfil the 'need to be needed', perhaps after children have left home.
"In some cases, the social support offered by an animal is greater than the support another human could offer."