Owning a pet has already been linked to lower stress and blood pressure.

And now scientists say pets could also protect us from memory loss in later life.

Owners of animals including dogs, cats and rabbits were found to have held on to more of their cognitive abilities when tracked over six years.

For the study, researchers tested more than 1,300 people with an average age of 65.

Fifty-three per cent of them had pets and almost a third of this group had owned their pet for more than five years.

The participants were asked to recall a list of ten words, both immediately and after five minutes.

They had to count backwards from 20, and backwards from 100 by subtracting seven from each number.

The study found that, after six years, long-term pet owners saw less of a fall in their average score on these tests than those without pets.

There is increasing evidence that stress can lead to cognitive decline and experts believe pets may help us to stay mentally sharp by reducing stress.

Those with dogs benefit from regular walks as exercise is linked to a healthier brain.

However, the study authors say people with better thinking skills may simply be more likely to have pets, as they can deal with their multitude of demands.

The University of Michigan Medical Centre study, which is not yet published, was presented at the annual meeting of the American Academy of Neurology.

Dr Tiffany Braley, who led the study, said: 'Prior studies have suggested that the human-animal bond may have health benefits like decreasing blood pressure and stress.

'Our results suggest pet ownership may also be protective against cognitive decline.'

Responding to the research, Dr Rosa Sancho, head of research at Alzheimer's Research UK, said: 'Humans love their animals, and pets can be an important source of companionship and comfort throughout our lives.

'While this US-based study linked owning a pet with some protection in memory and thinking decline, it can't tell us if these are long-term benefits, or whether owning a pet has any bearing on dementia risk.

'This research has yet to be published and it's not yet possible to unpick the reasons behind the link the researchers have observed.'