On average, chihuahuas are the world's smallest dog.

Dogs' nose prints are as unique as human fingerprints and can be used to identify them.

They have scent glands in between their paws.

Some dogs can smell dead bodies underwater.

They have about 1,700 taste buds.

On average, dogs have better eyesight than humans, though not as colorful.

The world's smallest dog on record was a Yorkshire Terrier, weighing in at about 113 g [4 oz].

The most dogs ever owned by one person were 5,000 mastiffs owned by Kubla Khan.