Dog Anatomy

Dogs grow in various sizes and shapes.

  • The Greyhound is the ‘Fastest Dog on Earth’ and can run 45 miles per hour for short periods of time.

  • The Irish Wolfhound is the largest dog standing 28 – 32 inches and weighing between 90 – 150 pounds. Irish Wolfhounds make excellent companions, however, their life expectancy is somewhat shorter than most dogs and is between 6 – 8 years.

  • The Great Dane is the tallest dog standing 30 – 34 inches and weighing 120 – 200 pounds. These too have a short life expectancy and the average age is under 10 years although some can live 12 – 13 years. The Great Dane originates from Germany.

  • The Chihuahua is the smallest dog standing at only 5 inches tall and weighing 2 – 6 pounds. Chihuahuas can live until they are 15 years old.

  • The St. Bernard is the heaviest dog. They are very strong, muscular dogs with powerful heads, however, they are extremely gentle and friendly dogs and very tolerant of children. They stand around 26 – 28 inches and can weigh between 150 – 210 pounds.

  • The worlds oldest dog was an Australian cattle-dog named Bluey who lived to the age of 29 years and 5 months.

Other breeds range in different sizes and weights between the above.

Below is a diagram of a dogs anatomy:

Dog Anatomy

The coat of a dog varies in colours ranging from all black, brown, beige and white to others being of a mix with light or dark markings and colourations on different parts of their bodies and faces.

Their fur ranges from short, smooth fur to long shaggy fur to soft and fluffy to hard and coarse. The shape of a dog is determined by three structures, head, body and legs.

  Short smooth fur Long fluffy fur
Shaggy fur Short soft fur

The shape of these structures vary greatly in the same way as their colours and hair characteristics. The two most common head shapes for a dog are a narrow skull with a long face, such as a German Shepherd and a short skull with a short face, such as a pug dog There are many variations to these shapes in between.

Dogs have 42 teeth. Six pairs of sharp incisor teeth are in front of the mouth, flanked by two pairs of large canine (‘dog’) teeth. The other teeth are premolars and molars. The incisors and the canines are very important because the dog bites and tears at its food with these teeth.

Dogs have fairly thin tongues which are used mainly for guiding food to the throat, for licking the coat clean, and for perspiration. When a dog is overheated, it cools off by hanging its tongue out and panting. As it pants, the evaporation of perspiration from its tongue cools the animal. The dog also sweats through the pads on its paws and very slighty through its skin.

Dogs ears either stick up or hang down. Dogs have extremely sensitive hearing and can hear far more high frequencies than human ears. This is why they respond to silent whistles.

A dog has three eyelids on each eye, the main upper and lower lids and a third lid hidden between them in the inner corner of the eye. The third eyelid can sweep across the transparent cornea of the eye and clean it like a windshield wiper.

The body of a dog contains most of its vital organs. The heart, lungs, stomach, and intestines are located there. So too are its genitals, kidneys and bladder. A dog has 13 ribs in its chest which wrap around the heart and lungs. Since these organs influence the animals speed and stamina, chest size can be an indication of these traits.

All dogs have 27 bones from the skull to the point where the tail begins. The number of tailbones, however and therefore the length of the tail, varies from breed to breed.

The front legs of a dog are called the ‘forelegs’ and the back legs are called the ‘hindlegs’. On each paw, they have 5 toes, however, one of these toes of called the ‘dewclaw’ and is too high up to be of any use. The paw has cushiony pads for each toe and 2 larger pads further up the paw. Dogs perspire (sweat) through their pads.

A dogs heart beats between 70 and 120 times per minute, compared to a humans 70 – 80 beats per minute. Dogs take between 10 and 30 breathes every minute. Dogs have a visual range of 250 degrees compared to the human range of 180 degrees. A dogs temperature is between 100.2 and 102.8 degrees Fahrenheit. The average lifespan of a dog ranges from 12 – 14 years. Each one dog year is equivalent to 7 human years.