Traci Wolfe, age 13, of Winston Salem, N.C., for her question:
HOW IS A DOG'S AGE DETERMINED?
Dogs were the first animals to be tamed by man. The favorite household pet can trace his ancestry back about 15 million years to an animal called the Tomarctus, a wolf like creature that is also related to the jackals, coyotes and foxes. Stone Age people more than 20,000 years ago used tamed dogs to help them track game.
Often called "man's best friend," the dog is a friendly and obedient animal. There are more than 36 million of them living in the United States today.
A dog's age is determined just like a person's age: each year both the person and the dog become one year older. If a dog was born on Washington's birthday last year, the animal will be one year old this year on the same holiday.
The average dog will live for about 12 or 13 years. Lots live to be 16 or older.
It is hard to compare the age of a dog to that of a person, however, because the dog develops at greatly different rates.
When a puppy is six months old, for example, he can actually be compared in development to a 10 year old boy. And when the dog celebrates his second birthday, he can be compared in developmental age to a 24 year old man.
After a dog's second birthday, each year he lives may be compared to about four years of a man's life. When the dog reaches his 16th birthday, he can be compared to an 80 year old man one of the marks of a dog's intelligence is his ability to obey commands. For the first three weeks of his life he knows nothing and needs only warmth from his mother and food. But in his fourth week the puppy can see, hear, smell and begin to learn.
Between the fourth to seventh weeks in a puppy's life, the young animal learns to play and respond to humans. From the seventh to the 12th week the puppy can learn simple commands. If "Let's go for a walk" is repeated several times before going out, the dog will come to know exactly what the person means.
Some dogs seem to have the power to reason and solve problems. Do they really have this power? There is much debate on this subject.
Dogs have retained many instincts from their wild ancestors. They still gulp and gobble their food as though they were keeping other animals from grabbing it. And they still turn around several times before lying down, in much the same way wild dogs trampled grass to make a sheltered bed.
A frightened dog still curls his tail between his legs to keep it out of the reach of enemies. And male dogs urinate on trees to tell other dogs they have been there.