Dogs have better night vision than humans.
Dogs have a much higher portion of rods in their retina. Rods are specialized to work under dim light conditions. Cones are geared more towards sharp vision and the perception of color. Humans have more cones than dogs. We’ve all seen that yellow glow in our dog’s eyes when we take a picture of them. That’s because of the reflecting tapetum behind the retina, which reflects light back at the retina that was not caught by the photosensitive cells. This gives your pup good vision in dim light conditions by giving the photoreceptors a second chance a catching the light. It’s been estimated that dogs need one-quarter the light that humans need to see at night.
Dogs have good motion perception
One study found that dogs could recognize a moving object at 900 yards. If the same object where not moving, the dogs could not discriminate it over 600 yards. I’ve tried this in the yard and it seems to be true. Something had the dogs’ attention, so I walked around the house to see what it was. They were looking in the opposite direction, so I stood about 25 yards from them quietly. When they turn around they seemed to look right passed me. I was still and they just ignored me. I started moving, and tails started wagging. Probably by my movement the dogs recognized it was me, but with out the movement, they seemed unsure???
Also, most humans can’t see Hertz (Hz. Or cycles) above 55 Hz. a second. Dogs can see up to 75 Hz. A TV flickers at about 60 Hz., so you don’t see it flicker. However, your dog can probably see the television flickering.
Field of View
Because of the shape of a dogs head, they have a better field of view than we do. Humans have a visual field of about 200 degrees. Dogs have about 240 degrees.
Dogs DO see color
Dogs do see color, they’re just color blind. Remember, they have more rods and less cones, which increases their night vision, but decreases their vision and color perception. We see a rainbow of violet, blue, blue-green, green, yellow, orange, and red. Your dog would see dark blue, light blue, gray, light yellow, darker yellow and very dark grey. Red is difficult for dogs to see.
It’s kinda funny that some dog toys and our hunting vests are bright orange. It’s great for us to see, but for our dogs the orange registers as yellow, just like the grass.
How Dogs Hear
First thing I asked was how can you tell what the dog hears accurately? The answer is they can measure brain responses to sound with certain devices. First on the topic of frequency range or sound pitch, Humans can hear sounds up to 20,000 Hz. If you could add 28 keys to the right-hand side of a piano, that’s about where we would stop hearing the sound. Dogs can hear up to 65,000 Hz. That would be the sound of 48 keys added to the right-hand side of the piano. That explains how you can have a silent dog whistle. Those whistles produce a sound at a higher frequency that what humans can hear, but your dog can still hear it.
Another cool thing is that if you have a deaf dog, get it a companion dog. The deaf dog will pay attention to its companion that can hear. By the other dogs actions, the deaf dog will pick up its surroundings.
The Big Sniffer
A dogs brain is generally one-tenth the size of the human brain, but the portion of the brain dedicated to analyzing smells is forty times greater than that of humans!!!!!!!! Your pup can identify smells about 1,000 to 10,000 times better than humans can.
This sounds crazy, but the ridges and dimples in your dogs nose are as unique as a human finger print. The book says some companies actually hold registries of nose prints as positive identification for dogs. To get a nose print, dry your dogs nose, and apply food coloring to a paper cloth. Dab it on the dogs nose and then use a piece of paper to make an imprint.
When a dog breaths or pants, air travels through the nasal passages, below the shelf, and down to the lungs. When sniffing, the dog can trap air and hold it in the nasal cavity; even while exhaling.
This is great stuff. Humans have sweat glands that release moisture to cool the body. Dogs only have these glands in the pads of their paws. A dog pants to increase its cooling capacity. When your dog is panting, it has turned off its scent-processing ability. To test this, when your dog is panting, hold a treat to its nose. The dog will stop panting briefly to smell the food. When your dog is panting, it is proven that its scent recognition is reduced by 40%!!!
Generally, humans have about 1 square inch of scent detecting cells. Dogs tend to have about 60 square inches of these odor analyzers. To put it in perspective, if one gram of butyric acid was evaporated into a 10 story building, we could barely smell it. If you evaporated the same amount of butyric acid into a 135 square mile area, and up to a height of 300 feet, a dog could still smell it.
Also, a hot sunny day, with no breeze is a terrible scenting condition. At dusk or dawn, with a cool ground, a bit of humidity, and a steady breeze is a GREAT scenting condition.
It’s documented that dogs can possibly smell cancer. In one case, a woman’s dog would continually sniff a certain spot of her pants. Over time, the dog would nip at a particular mole of this woman’s leg when she wore shorts; ignoring all the other moles. She went to the doctor and the mole was malignant. There is more than one occurrence of this.
More to come….
