Dog Anatomy: How dogs are designed
Although you wouldn’t know to look at him, your little Maltese or Shih Tzu, your goofy Pug or lovable Lab is actually a wolf in dog’s clothing. Wolves are powerful apex predators, designed for tracking and bringing down prey. Then with sharp teeth and strong jaws attacking, holding, and tearing the prey apart.
Although we have changed the appearance of dog breeds in myriad ways, the basic dog anatomy of the wolf is still there in the design of your dog. Dog anatomy is almost identical in wolves and domestic dogs. Like the wolf, a dog has:
- A skeletal structure designed for running and leaping.
- Loose and flexible front legs with disconnected shoulder bones (no bone attachment between the front legs and shoulders) which act as “shock absorbers” when running.
- Powerful, heavily muscled hind legs allowing for a burst of speed from a standing start as well as superior leaping ability.
- Small, tight feet, with fused wrist bones giving them the ability to make quick changes of direction when running at speed.
- They have a cardiovascular system build for endurance allowing them to stay on the track of prey for hours without tiring.
- Tails for signaling, an important asset for pack hunters.
- And of course, they have their specialized teeth, designed for catching, holding and attacking prey.
Other Interesting Facts About Dog Anatomy
Modern dogs come in a variety of coat colors and textures, most of them due to selective breeding, but amazingly recent research suggests that some of the changes may have occurred naturally once wolves began living near human settlements. All dog coat colors are variants of yellow or a mutation of the beta-defensin gene which produces a black coat color.
Dogs regulate their body temperature in a number of ways, through painting, releasing perspiration through the pads of their paws, and through the rete mirabile, a complex of small arteries and veins located at the back of the neck. This acts as a sort of heat exchanger by isolating body heat from the brain.
Dogs have 42 teeth – Six pairs of sharp incisors in the front of the mouth, two pairs of large canines (fangs) plus premolars and molars. The incisors and canines are particularly important because dogs bite and tear their food with these teeth.
Another interesting aspect of dog anatomy is that a dog’s eye has three eyelids, the upper and lower lids plus a third lid hidden among them. The third eyelid can sweep across the transparent cornea of the eye and clean it like a windshield wiper.
All dogs have 27 bones from the base of the skull to the point where the tail begins. However, the number of tailbones, and therefore the length of the tail, varies from breed to breed.
When a dog is stressed it may raise its hackles (the hair along the neck and spine). This is made possible by tiny muscles which are attached to each hair shaft where it emerges from the skin. A dog’s tongue is used mainly for guiding food down its throat, for releasing body heat, and for licking its coat. Dogs have a very poorly developed sense of taste allowing them to eat food that other animals would find offensive. The success of the dogs as a species is due mainly to dog anatomy being suited so perfectly for survival in diverse environments and situations.