The History and Future of Dogs

Dogs are popular pets. They are strong, weak, tall, short, heavy, and light. 35% of the people in the United States have dogs in their homes.

Fossils of the dog go back into the Mesolithic Period, about 12 thousand years ago.

The heaviest dogs are the St. Bernard and the Mastiff. They can weigh up to 200 pounds. The tallest dog is the Iris Wolfhound. The smallest dog is the Teacup Chihuahua, which only weighs about one pound.

Dogs can see in color but they are red-green color-blind. Humans can see much better in color than dogs.

Have you ever wondered how a dog hears a dog whistle?

The highest pitch a human can hear is 20,000 sound waves per second and a dog can hear up to 40,000 sound waves per second. The only time a human might hear a dog whistle is when a they are very young.

Have you ever wondered what it meant when a dog wags its tail?

When a dog wags its tail, it means it is feeling happy or friendly.