Poodle
While poodles might come in all shapes and sizes, every version of the breed holds the same intelligence. So much so that they are the second smartest dog breed. Although they are highly intelligent and simple to train, poodles struggle to solve problems like some other breeds in the world.
Border Collie
Many experts agree that border collies are the most intelligent breed of dog. Not only can they herd sheep in a way unlike any other breed, but border collies are thought to be almost as smart as humans. Their brains means they can be challenging to train as they pick up everything within moments.