
Smell
A dog interprets the world predominantly by smell, whereas a human interprets it by sight. While a dog's brain is only one-tenth the size of a human brain, the part that controls smell is 40 times larger than in humans. On average a dog’s sense of smell is about 1,000 to 10,000,000 times more sensitive than a human's. A human has about 5 million scent glands, compared to a dog, which has anywhere from 125 million to 300 million (depending on the breed). Ever wonder why your dog's nose is wet? The mucus on a dog's nose helps it smell by capturing scent particles. When a dog’s nose is dry, they may lick it to aid in scent.
A dog can sniff and breathe, but these are two different functions. Breathing is for air, but when dogs sniff with short breaths, they save some scent that does not get exhaled. When a dog is overheated and actively panting, its sense of smell is reduced by as much as 40 percent as it uses the air to cool itself rather than to smell.
The Eyes
Since dogs do not have a spoken language, their thoughts are more like a sequence of images, much like a child before it learns to speak.
A common question among humans is, "Are dogs color blind? Not exactly! Studies have shown that dogs see in various shades of blue and yellow. For example, a rainbow to a dog would be as follows: dark blue, light blue, light gray, light yellow, dark brownish yellow, and dark gray.
Dogs can see best at dusk and dawn. Their low-light vision is much better than a human, but not their overall vision. On average a dog's vision is approximately 20/75 whereas a human’s vision is considered perfect at 20/20.
The Ears
Puppies are born deaf and cannot hear until they are about 21 days old. Their eyes are also closed. During this time, they rely solely on scent to interpret their world. Dogs have 18 or more muscles in their ears, allowing them to be mobile, whereas a human has only 6 and can only move their ears slightly, if at all. Dogs with perked ears can usually hear better than dogs with hanging ears, especially if they can move their ears toward the sound.
Energy
Animals can feel the energy around them. While you can hide your emotions from another human, you cannot hide them from your pup! I guess it’s true—a dog is a man and a woman’s best friend!