Dogs are mammals in the canine family and a subspecis of the wolf
Based on DNA evidence, the wolf ancestors of modern dogs diverged from other wolves about 100,000 years ago, and dogs were domesticated from those wolf ancestors about 15,000 years ago. This date would make dogs the first species to be domesticated by humans. Dogs are the most common working and companion animals. They are man's best friend.
There are hundreds of breeds of dogs.
There is a great deal of variation in height, weight, color, texture, atomical features, and behavior.
Labrador Retriever has been the United States's most commonly registered breed of dog since 1991. However, even within parts of the United States, popularity varies.
Dogs are predators and scavengers, possessing sharp teeth and strong jaws for attacking, holding, and tearing their food.
Like many other predatory mammals, the dog has powerful muscles, fused wristbones, a cardiovascular system that supports both sprinting and endurance, and teeth for catching and tearing.
A dog can identify a sound's location much faster than a human can, as well as hear sounds up to four times the distance that humans are able to.
Dogs have nearly 220 million smell-sensitive cells over an area about the size of a pocket handkerchief.
Dogs are very social animals, but their personality and behavior vary with breed as well as how they are treated by their owners. Dogs are valued for their intelligence.
Dogs are susceptible to various diseases, ailments, and poisons, some of which affect humans in the same way, others of which are unique to dogs. Dogs, like all mammals, are also susceptible to heat exhaustion when dealing with high levels of humidity and/or extreme temperatures