Dogs can remember names of toys years after not seeing them, study shows

Dog owners may have trouble remembering which toy is Mr Squeaky, but such names can be seared into the memory of their pets, researchers have found.

Scientists previously discovered some dogs have a remarkable ability to learn the names of toys, with a border collie known as Chaser having learned the labels of more than 1,000 objects.

Related: Who’s a clever dog? Scientists study secrets of canine cognition

Now researchers have discovered some dogs can remember the name of a toy even when they have not seen it for two years.

Shany Dror of Eötvös Loránd University in Hungary, the first author of the study, said the results showed such dogs stored object names in their long-term memory, rather than simply having their memory refreshed by their owners through frequent play with the item.

Dror added the findings could have implications for understanding the evolution of human language, given memory is one of its many components. “Why is language uniquely human? To understand that, we need to understand what parts of language are available in other animals in which part are not,” she said.

Writing in the journal Biology Letters, Dror and colleagues report how they studied five dogs who, in earlier research, had learned the names of 12 new toys. These toys were subsequently put away for two years.

In the new study, the dogs’ owners brought the toys out of retirement. Three dogs had all 12, another had 11 toys and one dog had only five toys as some had been misplaced.

After allowing their dog to inspect the objects, each owner placed five or six of the “test” toys in one room in their home, alongside eight of their dog’s other toys. The owners then moved into a second room and asked their dog to get each of the test toys – one at a time. To minimise disruption, the owner replaced the chosen toys only when there were just three test toys left in the pile. The researchers watched online via video-recording devices.

The experiment was carried out twice for each dog, and was also repeated for four of the dogs using their remaining test toys.

The results reveal that, overall, the dogs picked the correct toy 44% of the time on average – with some having a success rate of up to 60%. These figures, the researchers add, are far above the level expected by chance.

The results were driven by the prowess of four dogs, with these canines remembering the names of between three and nine of their test toys.

The team stress that just because some dogs can learn object names, not every canine can do so, with the factors behind the skill still unclear.

However, Dror noted dogs with the talent often had owners who spent a lot of time engaging with them. “The more you invest in your dog, the more you will get back from the relationship,” she said.