Researchers at the University of British Columbia have found that the border collie is the most intelligent breed of dog.
The study measured intelligence based on a dog's ability to learn and perform new commands.
Border collies were able to learn new commands after only five repetitions and could remember them for up to two months.
Other breeds that scored high on the intelligence scale included poodles, German shepherds, golden retrievers, and Doberman pinschers.
The study also found that smaller breeds, such as Chihuahuas and Shih Tzus, were not as intelligent as larger breeds.
The researchers hope that their findings will help dog owners better understand their pets and improve training methods.