Whisky — a six-year-old border collie — has learned the names of 90 different toys on her own and can fetch them on request, researchers have found.

The clever canine has learned to differentiate between balls, Frisbees, rings, or ropes — and can even categorise new toys into these groups.

When the researchers first met Whisky, she already knew the name of 59 toys, but her owners say that she has now learnt around 31 more.

Whisky may have a little way to go before she breaks the all-time record for the cleverest dog, however.

Fellow border collie Chaser, of South Carolina — who was owned by psychologist John Pilley — is said to have learnt more than 1,000 words before she died last year.

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'At first it was hard for me to believe that a dog learned the name of so many toys, but after several days of rigorous testing, I had to change my mind,' says Claudia Fugazza of the Eötvös Loránd University in Hungary. Pictured, Dr Fugazza (left) with Whisky and her owner

Whisky — a six-year-old Border Collie — has learned the names of 90 different toys on her own and can fetch them on request, researchers have found. Pictured, Whisky and her toys

'At first it was hard for me to believe that a dog learned the name of so many toys, but after several days of rigorous testing, I had to change my mind,' says lead researcher Claudia Fugazza of the Eötvös Loránd University in Hungary.

'We noticed that, among her toys, Whisky had several exemplars belonging to one of 4 categories: she had 10 different balls, 7 different rings, 4 different ropes and 4 different Frisbees,' the animal behaviour expert added.

The owners refer to each of these toys by both an adjective and a category name — for instance, the 'small Frisbee' or the 'colourful ring'.

Whisky's owners had not explicitly trained the clever collie to learn different categories — but appeared to have picked them up in the course of play-centred interactions with her humans.

'This provided us a rare opportunity: testing whether a dog had spontaneously formed some mental categories, simply by being exposed to their exemplars — pretty much like a human child would do,' Dr Fugazza said.

'Most studies on the ability of non-human animals to categorise are conducted after the subjects are extensively trained to recognize categories with a given set of exemplars,' added paper co-author and animal behaviour expert Ádám Miklósi.

'Only after reaching the predetermined criterion, they are tested on their ability to categorise novel items belonging to those learned categories.'

Moreover, the clever canine has learned the different types of toys — such as balls, Frisbees,rings, or ropes — a can even categorise new toys into these groups. Pictured, Whisky the border collie with her owners

When the researchers first met Whisky, she knew the name of 59 toys — but her owners say that she has now learnt around 31 more

To put Whisky to the test, researchers presented her with sets of four new toys that she had never seen previously — one from each of the four categories of balls, Frisbees, rings and ropes.

Whisky owners then asked the dog to fetch a toy from a given category — for example by saying 'bring me a ring'.

The researchers found that Whisky chose the correct category of toy from the new playthings more often than pure chance should allow.

Furthermore, her accuracy improved when she was allowed to spend a little time playing with each toy with her owners, even though they were not allowed to name the new objects.

'This suggests that, although Whisky relied on the visual features of the toys (e.g., their shape), experiencing the function — for example, how to play with them or the way they move — helped her to make a choice,' said Dr Fugazza.

To make sure that Whisky wasn't selecting the toys based on visual cues from her owner — such as, for example, pointing or looking at the correct item — the researchers placed the toys out of sight of her owner.

'We noticed that, among her toys, Whisky had several exemplars belonging to one of 4 categories: she had 10 different balls, 7 different rings, 4 different ropes and 4 different Frisbees,' Dr Fugazza said. Pictured, Whisky plays outside with her owner

Whisky's owners refer to each of her toys by both an adjective and a category name — for instance, the 'small Frisbee' or the 'colourful ring', pictured

Whisky's owners had not explicitly trained the clever collie to learn different categories — but appeared to have picked them up in the course of play-centred interactions with her humans

In some ways, the researchers say, Whisky's skills are similar to those of young babies when learning their first words.

'Whisky’s achievements mirror human capacities more closely than typical animal studies in two key factors: the lack of specific training for categorisation prior to the tests and the use of words to indicate the categories,' explained Professor Miklósi.

'Since this study was conducted on one subject and dogs with vocabulary knowledge are extremely rare, this capacity should not be automatically extended to all the dogs,' he added.

'However, the results do reveal that spontaneous categorisation in absence of specific training is not a mental skill that is present only in humans.'

The full findings of the study were published in the journal Scientific Reports.

'This provided us a rare opportunity: testing whether a dog had spontaneously formed some mental categories, simply by being exposed to their exemplars,' Dr Fugazza said. Pictured, Whisky listens to her owners asking her to fetch a particular toy

'Most studies on the ability of non-human animals to categorise are conducted after the subjects are extensively trained to recognize categories with a given set of exemplars,' added paper co-author and animal behaviour expert Ádám Miklósi. Pictured, Whisky and her owner

To put Whisky to the test, experts presented her with sets of four new toys that she had never seen previously — one from each of the four categories of balls, Frisbees, rings and ropes. Whisky owners then asked the dog to fetch a toy from a given category — for example by saying 'bring me a ring'. Pictured, Whisky poses with Dr Fugazza (left) and her owners (right)

The researchers found that Whisky chose the correct category of toy from the new playthings more often than pure chance should allow. Furthermore, her accuracy improved when she was allowed to spend a little time playing with each toy with her owners, even though they were not allowed to name the new objects. Pictured, Whisky high fives Dr Fugazza