1. Your dog's nose is wet because the wetness helps it absorb scent chemicals. It's just one of the things that makes a dog's sense of smell millions of times better than ours.
2. Dogs poop in alignment with Earth's magnetic fields.
3. The Norweigen Lundehund has six toes on each foot. It's the only dog with this unique characteristic.
4. The largest dog on record is Zeus, a Great Dane who measures 44 inches from foot to withers.
5. The smallest dog on record (measured in length, not weight) is Heaven Sent Brandy, a Chihuahua who measured just 6 inches from the nose to the tip of her tail.
6. Dogs can understand somewhere around 165 words.
7. Dog urine can corrode metal.
8. The largest number of puppies birthed in one litter was 24, a record held by Tia, a Neapolitan mastiff.
9. Dogs can smell disease. Research conducted at the Schillerhohe Hospital in Germany found that because dogs can smell organic compounds that humans can't, they can detect cancer and other diseases.
10. Dogs have three eyelids. Their third eyelid is called a "haw" and it helps keep the dog's eyes moist.
11. Dogs have unique "fingerprints" — their noses. Like a human's fingerprints, a dog's nose print is completely unique to that dog.
12. The world's oldest dog lived to be 30 years old. Her name was Maggie and she was an Australian kelpie.
13. The oldest intact fossil of a pet dog dates back 33,000 years.
14. Sergeant Stubby, who served in World War I, is the only dog in the U.S. to ever reach the rank of Sergeant.
15. The Alaskan Malamute can withstand temperatures as low as -70 degrees Fahrenheit.
16. Helen Keller brought Akitas to the U.S. from Japan.
17. For running purposes, a dog's shoulder blades are not connected to the rest of its skeletal system.