The reason Fido won’t fetch? He’s hit middle age...

They say you can’t teach an old dog new tricks – but that might be simply because they’ve become tired of life, a study suggests.

Dogs hit middle-age just like we do, it seems, becoming less excitable and less interested in new experiences as time wears on.

And researchers believe the stage of life comes sooner than expected, with changes in temperament seen from the age of three.

They think this is because older pets have experienced more big upheavals, such as moving home, and as a result may be tired of novelty. Animal behaviour experts studied 217 border collies, aged six months to 15 years, in 15 different situations to test how they reacted.

each was placed for an hour in an unfamiliar room, which was filled with things of interest such as bags and boxes.

The researchers found that the ‘middle-aged’ dogs were far less interested in exploring the room, while the puppies – under a year old – bounded off to investigate rustling noises.

The older dogs also looked for their owners or followed them far more often than puppies.

The study, which was led by eotvos Lorand University in hungary and published in the journal Scientific Reports, found dogs also had a ‘ teenage’ period, becoming less active between the ages of one and two.

And dogs showed signs of memory loss in later life, becoming worse at problem- solving tests over the age of eight. Dr Lisa Wallis, co-author of the study from Liverpool University, said: ‘People and dogs are more alike at different ages than people might think.

‘Middle-aged dogs may be less excited about novel objects and environments because they have lived a bit, like we have, and know that things which seem exciting at first often don’t lead to much.’