Pet tennis ball Dog

• Canines left on own start 'whining and not coming when called': study
• Yet playing with our dogs is key to their happiness, new research shows
• But just one in five owners play with their dogs up to six times a day
• Research by Bristol University found play was key to their quality of life

They are called a man's best friend, and for good reason - owners who don't play with their dogs find their pets suffer behavioural problems such as anxiety and aggression, according to a survey.

The canines show symptoms such as 'whining and jumping up, as well as pulling on the lead and not coming when called', the study of 4, 000 dog owners revealed.

And scientists are beginning to agree that play is the key to a dog's happiness.

Research by Bristol University found that play was the key to a dog's happiness and their quality of live, according to a survey of 4, 000 owners. It also revealed that 'fetch' was a dog's top game (file photo)

The research showed just one in five owners played with their dogs six times a day, while half played twice or three times a day with their pets and 10 per cent played just once.

He said the study, carried out by Emily Blackwell of Bristol University, found there was 'a growing acceptance' that the 'frequency of play for dogs is a really good indicator of their quality of life'.

The survey, which will be revealed tomorrow on the Channel 4 programme Dogs: Their Secret Lives, also shows that a dogs' favourite game is 'fetch', according to 43 per cent of owners.

But Laura Dobb, who took part in the show, said if she throws her rescue dog Nash a tennis ball he will 'throw it up in the air' but won't bring it back.

The type of game owners played with their pet was important, according to Mr Evans, who said that owners needed to find out which ones their animals enjoyed rather than 'impose a game'.

If owners chose to play tug with their pet, he added that it was 'rubbish' if they felt they had to let their dog win out of fear the animal would 'dominate your whole life'.