Dogs. They’re just the best, aren’t they? But how much do you really know about your canine companion? Test your knowledge by checking out these 25 fun facts about man’s (and woman’s) best friend.

  1. There are approximately 78 million pet dogs in the U.S., living in 39% of American households.
  2. In 2015, the most popular name for a male dog was Max, while Bella was number one for females.
  3. An estimated 78% of pet dogs are spayed or neutered, compared to 88% of pet cats.
  4. The latest research indicates dogs have been domesticated for anywhere from 27,000 to 40,000 years.
  5.  An Australian Cattle Dog named Bluey holds the Guinness world record for the oldest dog ever. He lived for 29 years and 5 months.
  6. The tallest living dog on record is Zeus, a Great Dane who measures 44 inches at the shoulder. The smallest is Milly, a Chihuahua who is only 3.8 inches tall.
  7. A dog’s sense of smell is at least 1,000 times greater than that of a human.
  8. Dogs have 220 million olfactory receptors while humans have a paltry 5 million.
  9. The ridges and creases in a dog’s nose are as unique as fingerprints. No two are alike!
  10. Contrary to popular belief, dogs can see color but they see it differently than we do. They can see bluish and greenish shades but not reddish ones.
  11. The ears of a dog can move independently. That’s because they have twice as many muscles in their ears as humans.
  12. Dogs can hear a much higher frequency of sounds than we can, meaning the world is a very noisy place for them.
  13.  For their Sgt. Pepper album, the Beatles recorded a sound only dogs can hear and placed it in the song, “A Day in the Life.”
  14.  The average dog can recognize around 150 words
  15.  A Border Collie named Chaser knows more than 1,000 words, including verbs, adverbs, and prepositions.
  16.  The mental ability of most dogs is equivalent to that of a 2-year-old child.
  17. When it comes to intelligence, Border Collies come in first and Poodles second.
  18.  French Poodles actually originated in Germany, not France.
  19. The majority of U.S. presidents have owned dogs. The first to receive extensive press coverage was Warren G. Harding’s Airedale, Laddie Boy. He even had his own seat at cabinet meetings!
  20.  Mongolian general Kublai Khan kept 5,000 Mastiffs as part of his army.
  21.  Over 2,500 dogs serve in the U.S. military today.
  22.  Sergeant Stubby, a bulldog mix, was the most decorated war dog of World War I and the only dog to be promoted in rank through combat.
  23.  Like humans, dogs have a paw preference, generally favoring either the left or right paw to perform tasks
  24.  Dogs read human faces and expressions from left to right, which is the same thing humans do with each other. Dogs don’t do this with any other species and may explain why they’re so good at reading our emotions.
  25.  Studies have shown that people with dogs are healthier than those without. Overall, dog parents have lower blood pressure, lower cholesterol and are less prone to depression.