Dogs are popular pets throughout the world.
They were one of the first animals to be domesticated.
Today they can found all over the world.
Dogs resemble other wild animals like wolves, coyotes, foxes and jackals that belong to a small family of meat eating mammals.
There are hundreds of breeds of purebred dogs in the world.
A purebred is a dog whose sire (father) and dam (mother) belong to the same bred.
A crossbred is a dog whose parents belong to different breeds.
Kennel associations in different countries recognize different breeds of dogs and categorize them in groups.
Few of these groups are - 1.
Sporting Dogs 2.
Hounds 3.
Working Dogs 4.
Herding Dogs 5.
Terriers 6.
Toy Dogs 7.
Non-sporting Dogs The size, shape, and other characteristics of a dog's body vary widely from breed to breed.
But in spite of their differences, all dogs share certain basic physical features.
These are the coat, the body structure, body functions and senses.
Coat: Most dogs have two coats - an outer coat of long guard hairs and an undercoat of shorter, fluffy hair.
The guard hairs protect the dog against the rain and snow, and the undercoat keeps the dogs warm.
Most dogs shed the undercoat as spring approaches and grow it back in autumn.
Dogs have whiskers around their mouth.
These are long and stiff and are highly sensitive touch organs.
The texture, length and color of the coat differ greatly among various breeds.
Some may have long straight coats while some may have short coarse coats.
Body Structure: the body structure is determined by the dog's skeleton.
All dogs of the same breed have the same number of bones.
But the shape and size of the bones varies from breed to breed.
Dogs have four toes on each foot and the bottoms of the paws have soft pads covered by tough skin.
The skull varies in shape from breed to breed.
Puppies have 32 temporary teeth which are replaced by 42 permanent teeth in adults.
The ears vary in shape and size among breeds.
Body Functions: differ only slightly from those of human being.
For example, a dog's heart beats 70 to 120 beats a minute while the normal body temperature of a dog is 101.
5 degrees F.
the human heart beats at about 70 to 80 beats a minute and the normal body temperature is 98.
6 degrees F.
Dogs cannot cool their bodies by sweating.
Instead they stick out their tongues and pant.
As a dog pants, water evaporates from the tongue and mouth and cools its body.
Senses: The smell is the most highly developed sense in dogs.
Dogs use smell to recognize, the same way humans use sight.
A dog's nose can pick out odors that are faint for a human nose to detect.
It can pick out an object that a person has touched from a group of objects.
The nose has a gland that keeps it moist.
They also lick their noses to keep them moist.
Dogs can hear far above the limit of human hearing.
They can also hear at muck greater distances than humans can.
The hearing is highly developed to recognize different complicated sounds.
Dogs have poor eye sight.
They can detect motion which makes them good hunters.
They are color blind and see green, yellow, orange and red as the same.