Dog

The dog (Canis familiaris or Canis lupus familiaris) is a domesticated animal that comes from wolves. People have kept dogs as pets for a very long time, longer than they have farmed crops.

Dogs come in many different shapes, sizes, and colors. They have strong jaws with many teeth and are very good at smelling and hearing, even better than humans. However, their eyesight is not as sharp as ours.

Dogs help people in many ways. They can help with hunting, herding animals, pulling loads, keeping us safe, being friends, giving therapy, helping disabled people, and even working for police and the military. Because of this, dogs have learned to understand and talk to humans in special ways.

There are a lot of dogs in the world, and they live in many countries. Dogs are very popular pets, especially in the United States.

Taxonomy

Further information: Canis lupus dingo § Taxonomic debate – the domestic dog, dingo, and New Guinea singing dog

Dogs belong to the Canidae family. They are a subspecies of Canis lupus, just like wolves and dingoes. Scientists think dogs and wolves separated a long time ago, between 27,000 and 40,000 years back. Dogs were first tamed by hunter-gatherers at least 14,000 years ago. One of the oldest known dogs was buried with humans in Germany.

Domestication

Main article: Domestication of the dog

The oldest remains of a tamed dog were found in Bonn-Oberkassel, Germany. This dog was buried with a man and a woman. It had been very sick as a puppy, which shows that people cared for it. This means dogs were the first animals to live with humans, even before farming started. DNA studies suggest dogs were first tamed over 25,000 years ago, maybe in Siberia. They then spread around the world with people.

Breeds

There are about 450 official dog breeds, more than any other animal. Most of these breeds started during the Victorian era when people chose dogs for certain traits. Today, dog breeds come in many sizes, shapes, fur types, and behaviors. These differences help dogs do many jobs, like guarding, herding, hunting, and finding smells.

Anatomy and physiology

Dogs come in many sizes, from very large like the Great Dane to very small like the Chihuahua. All healthy dogs have the same number of bones, but their skeletons look different. Their bodies are made for running, with special bones and muscles that help them move fast and easily.

Dogs can see, hear, smell, taste, and feel their way through the world. Their sense of smell is very strong—much better than humans'. They can see colors, but not as many as we can. Dogs use their tails to show their feelings and to keep their balance. Their coats come in many types, from thick and double-layered to thin or even hairless.

Health

Dogs can have many health problems, both ones they are born with and ones they develop later. Some common issues include problems with their breathing, heart, blood, digestion, liver, pancreas, kidneys, urinary tract, hormones, nervous system, muscles, bones, skin, and eyes. Dogs can also get sick from parasites like fleas, ticks, and worms, and from viruses such as distemper and parvovirus.

Vaccines can help protect dogs from many of these diseases. Dogs can sometimes get very sick if they accidentally eat harmful things like certain human medicines, chocolate, or cleaning products.

Older dogs often face health challenges such as cancer, heart problems, and kidney issues.

Behavior

See also: Dog intelligence

See also: Dog behavior § Behavior compared with other canids

Dogs have lived with humans for thousands of years. This has changed how they behave. They can understand and talk to humans better than many other animals. Scientists think dogs have special skills that help them connect with people, like how children learn and play.

Dogs were bred to be friendly and helpful. Small changes in their genes affect how they feel and act. These changes help dogs be less scared and more friendly. Some dogs might feel worried or act in a way that seems angry because of things that happened before, but most dogs are happy to be near people and other animals. Dogs also have natural instincts, like chasing after moving things, which they can use when hunting. They can swim, though not all dogs are natural swimmers.

Ecology

Dogs are often kept as pets by people all around the world. Many homes have dogs living in them.

Dogs can meet other wild animals sometimes. Animals like wolves, coyotes, and big cats may try to attack dogs. In places like New Zealand, where there were not many native land animals, dogs have affected the local wildlife.

Roles with humans

Main article: Human–canine bond

Dogs have lived with humans for a long time. They began as animals that hunted and looked for food. Dogs learned helpful behaviors from wolves, such as understanding body language. These skills make dogs easy to train and great friends.

Dogs can help with many tasks. They assist with hunting, guiding animals, carrying heavy things, and keeping homes safe. They also help police and support people with disabilities. Because of these helpful roles, dogs are often called "man's best friend" around the world.

Terminology

The word Dog means the whole group of these animals or any male dog. A female dog is called a Bitch. Young dogs under 12 months old are called Puppy or pup. The male parent of puppies is called the Sire, and the female parent is called the Dam. All the puppies from one birth are called a Litter. The act of a female dog giving birth is called Whelping. Puppies that still need their mother’s care are called Whelps.