Is My Dog Colored Blind?

 

Science has established that Dogs share the same 5 senses that people have; they see, hear, touch, smell and taste. Yet some of the dog’s senses are less developed and others extraordinarily more sensitive than ours. Knowing this can help us figure out just what our dogs are up to most of the time.

 

Sight

The secret is our dogs can see color but they do see color differently than we do. Our vision is made up of these two different aspects; color vision and visual acuity. There are 2 types of cells in the retina that receive light called rods and cones. The rods help us when sensing motion and work best in low lighting and cones help in the brightest light and can detect different colors. People and dogs have more rods then cones. People have 3 types of cones and dogs have 2 types of cones. The three types of cones give us our basic color vision. This suggests that the dog has vision similar to a person who is red-green colorblind.

Our visual acuity is the ability to see the details of an object separately and clear. Our acuity is measured in “cycles per degree”, which I understand this to mean how many lines you can distinguish as being separate in a degree of visual field. Through testing we know that people see 30 cycles per degree and that dogs see 12 cycles per degree. This would suggest that the dog does not see the detail as we do.

But dogs have it hands down in detecting motion and our dogs’ night vision is better than ours. Dogs have an additional reflective layer in the eye called the tapetum lucidum, this reflects light back into the receptor cells of the eye, which not only increases their night vision, but gives the dog spooky glowing eyes in the dark.

I recently learned another unique feature to our dogs’ eye; the nictiating membrane. This membrane is also known as the third eyelid, it is whitish pink in color, and it is found under the other eyelids in the inside corner of the eye, near the nose. The eyelid will extend up when it is needed to protect the eyeball.

Hearing

The average dog can hear up to 4 times better than people. This is due to the ear shape and deeper ear canal of the dog, which creates a funnel to carry the sound. Our dogs are bombarded with sound stimulation all day, they have at least 15 different muscles that move their ears in all directions, plus they can move one ear at a time, and independently of the other gathering twice as much sound. This is really cool for our dogs but this does require frequent preventive ear cleaning to avoid common ear disorders found in dogs.

Touch

If you have ever seen the relationship between a mother dog and her pups you would know just how important touch is to the dog. Dogs being the highly social animal that they are love to rub and touch. Puppies are born with sensory receptors in their face so they can find their mother before their eyes ever being to open. The dogs skin is thinner and much more sensitive than human skin and this is why many shampoos made for people can be irritating to their skin.

Smell

Olfactory receptors give us the ability to smell and it is believed that dogs have estimated 2 billion versus peoples’ 40 million receptors. Dogs are commonly used in our workforce because of their awesome tracking ability, finding the missing, follow the scent of other animals or sniffing out drugs. The dog can detect the change of character of other dogs, or people just by detecting the slights increase or decrease of their hormonal levels, like sweat. Their unique ability of smell can look like a sixth sense. Smelling is a dog’s way of recognizing the world around him, as we use image maps to guide our way, they have a built in smell map of their world.

Taste

The dogs’ ability to smell is closely linked to his taste buds, although it is strange that the smellier the better for the dog. Dogs seem to dive right in and ask questions later, I don’t know how they have time to taste most of what they eat. I have seven dogs some want to snatch the food from my hand and swallow it whole, and then our Poke wants to lay her treat at her feet on the floor and dare the others to go for it.

All these wonderful senses are rushing over our dogs at any given moment and much of their behavior if not all can be explained by understanding their senses. Our dogs long to please us and know how their senses relate to the world can help you with their health, training, and everyday care.

© Sensibledogs.com

 

Sources:

Coile, D. C. (1998a). Bringing Dog Vision into Focus. Dog World, March 1998. Pps. 30-35.

Animaleyecare.com

Merck/Merial. The Merck/Merial Manual for Pet Health, September 2007, Pgs. 3-7.