If you are looking for a healthier life, get a dog. Scientists have long believed that the companionship of a pet can be good for you, but new research suggests that dog owners are physically healthier than cat owners.

According to Deborah Wells from Queen's University, Belfast, dog owners tend to have lower blood pressure and cholesterol levels, possibly thanks to regular walks with their four-legged friends.

Writing in the British Journal of Health Psychology, Dr Wells said that dog owners appear to suffer from fewer minor ailments as well as fewer serious medical problems.

In a review of dozens of previous studies, Dr Wells found that dogs also seem to aid recovery from serious illnesses, such as heart attacks. One study published in 1995 found that dog owners were more likely, by about 8.6 per cent, to be alive one year after a heart attack than those who do not own a dog.

Dr Wells said: "It is possible that dogs can directly promote our well-being by buffering us from stress. The ownership of a dog can also lead to increases in physical activity and facilitate the development of social contacts, which may enhance physiological and psychological human health in a more indirect manner."

One British study found that the presence of a dog can help chronically ill children endure potentially painful medical procedures.

With their heightened sense of smell, dogs also appear to be able to sniff out malignant melanomas, a kind of cancer, or the onset of low blood sugar in diabetics, research suggests.

A study in Israel, meanwhile, suggested that pets can help people with schizophrenia to feel calmer and more motivated.