Understanding a Dog's Senses

Humans and dogs have the same senses: hearing, touch, sight and smell. But, it pretty much ends there in regards to equality. A human generally uses their senses in this order: hearing--> seeing--> smelling--> touch. Whereas a dog uses them in this order: smelling--> seeing--> hearing--> touch. In this post, I am going to break down each sense and describe the variations between a human and a dog.

The Nose:
 A dog's brain is about 1/10 the size of a human brain, BUT the part of the brain that controls smell is about 40 times larger in a dog than human. Pretty impressive, right? Depending upon the breed, A dog's sense of smell is 1,000- 10,000,000 times stronger than a human's. Dogs have about 125-300 million scent glands compared to a humans measly 5 million. Dogs can smell things that humans can't even fathom.... like emotions. We humans usually rely on our sight to tell us the subtle clues of how a person is feeling. Though, we can easily be tricked by a feigned smile or a "I'm fine". Dogs, on the other hand will smell right through that masquerade right to the emotional pheromones emitted by your body. Which is why, if your dog has been acting depressed or anxious, you should examine your own emotions and lifestyle. It could be that your dog is worried, because you are worried. Or, if your dog has suddenly started obsessively smelling a specific part of your body, you might want to go get a physical check-up from your doctor. A dog's smell is so great, it can smell subtle changes in your body chemistry that could be an illness.

Other smelling facts: A dog's wet nose is mucous that helps trap scent particles onto the nose, thus allowing a greater examination of "the smell". AND a dog is able to move both nostrils independently. This allows them to figure out the direction of "the smell". 

Eyes:
Most humans can see in color. Dogs, on the other hand, see in various shades of blue and yellow. Let's examine some colors and compare it to what a dog actually sees:

• Purple and Blue = Blue 
• Greenish blue = gray
• Red = black or dark gray
• Orange, yellow and green = yellow

Let's say you throw an orange ball upon some green grass, your dog will probably use more of his/her sense of smell to find the object than sight. To the dog, both the ball and grass are the same color---yellow. Dogs also see best at dusk or dawn and see moving objects better than humans. If your dog is staring at a television, it not only sees the picture we humans see, but it also sees the tiny flickering lights that human eyes don't detect. This does not mean that a dog's sight is superior to a humans, though. On the contrary. A normal human's eyesight is 20/20 whereas a dog's is about 20/75. Further more, a human can see close up and far away better than a dog.

Hearing:
When a dog is born, it cannot hear until it is about 21 days old. But once a dog's hearing is fully developed, they can hear 4 times the distance of a human. Dog's can also hear higher pitches. Depending upon the breed, a dog's hearing range is about 40- 60,000 Hz. Whereas a human is at about 20-20,000 Hz. This is why a dog may get upset by loud noises or the vacuum cleaner. A loud noise is REALLY LOUD to a dog and the vacuum cleaner may be giving off a super annoying high pitch noise that we humans can't detect. A dog also has about 18 muscles in their ears. This allows them to move their ears in all directions in order to detect the direction of a sound. A human has about 6 muscles, which is why we can maybe wiggle our ears at best.

Touch:
A dog's paw pads are made up of fat, connective tissue and really thick skin. This allows them to have great cushioning and insulation from cold and hot temperatures. That doesn't mean that their feet are invincible. Humans still need to pay attention to really hot pavement and icy snow to prevent blisters and cuts on a dog's paws. A dog's paws are naturally pretty rough. But, if you notice a smoothing away of the pads, you may need to examine the surface your dog walks upon. Pavement can do this to the paw pads and may need to be swapped out to a softer terrain like grass.

As you can see, humans and dogs may have the same senses: sight, hearing, smell and touch. But, they are not made equal. Which is why it is extremely important when training and understanding your dog, that you think about how your four-legged family member is perceiving the world. Humans have a tendency towards anthropomorphism --- putting human traits and emotions upon non-human animals---which often leads to behavioral problems in our canine friends.