All dogs are probably descended from an animal called Tomarctus.
This animal lived approximately 15 million years ago.

Stone-aged people tamed dogs to help them track game. About eight thousand years ago, ancient Egyptians raised Saluki hunting dogs. Saluki is an arabic word meaning noble one. These dogs are probably the oldest known breed.

Argos or Argus, Ulysses' hunting dog, was the only creature to recognize the Greek hero when he returned home disguised as a beggar after 20 years of adventure.

Cerberus, the three-headed dog of Greek mythology, guarded the gates to the underworld.

Laika became the world's first space traveler. Russian scientists sent the small animal aloft in an artificial earth satellite in 1957.

The basenji, an African wolf dog, is the only dog that cannot bark.

Irish Wolfhounds rank as the largest dog, and Chihuahuas as the smallest dog. The St. Bernard is the heaviest dog and other breeds range in size between these extremes.

A dog can hear sounds 250 yards away that most people cannot hear beyond 25 yards. The human ear can detect sound waves vibrating at frequencies up to 20,000 times a second. But dogs can hear sound waves that vibrate at frequencies of more than 30,000 times a second.

Dogs cannot see as well as humans and are considered color blind. A dog sees objects first by their movement, second by their brightness, and third by their shape.

A dog's heart beats between 70 and 120 times a minute, compared with a human heart which beats 70 to 80 times a minute.

A female carries her young about 60 days before the puppies are born.

You don't say...

• "A barking dog never bites."- describes people who sound more dangerous than they really are.
• "Barking up the wrong tree." - means to look for something in the wrong place.
• "Dog in a manger." - describes a person who keeps others from using something that he himself cannot use.
• "Let sleeping dogs lie." - means to leave a situation undisturbed.
• "Tail wagging the dog." - means that an unimportant member of a group is actually directing everyone's activities.
• "You can't teach an old dog new tricks." - is often used to describe a person who refuses to change their ways, or to learn a new way of doing things.