Post on 31-Jul-2015
Lynn Barber
Dogs Trust
The 5 Senses of the Dog
The 5 Senses
• Sight
The 5 Senses
• Sight
• Hearing
The 5 Senses
• Sight
• Hearing
• Touch
The 5 Senses
• Sight
• Hearing
• Touch
• Smell
The 5 Senses
• Sight
• Hearing
• Touch
• Smell
• Taste
Sight
Sight
• Dogs possess only two types of cone instead of three.
Sight
• Dogs possess only two types of cone instead of three.
• Dogs are red-green colour blind.
Sight
• Dogs possess only two types of cone instead of three.
• Dogs are red-green colour blind.
• They see a lighter and less detailed world when compared to humans
Sight
Sight
Peripheral vision is better than humans
Sight
Peripheral vision is better than humans
but distance is not judged quite as well. Dogs excel at night vision and the detection of moving objects.
Sight
Colour
Dogs see something like a human deuteranope,
that is, they are red-green colour blind (occurs in 4% of male humans). Simply put, this is due to having only 2 cone types rather than 3 (light sensitive cells include cones and rods).
Sight
Detail or Acuity
Since dogs have no fovea (or area with 100% cones), their estimated eye for detail is (roughly) 6 times poorer than in an average human.
Sight
Night Vision
Dogs have much better night vision for 2 reasons:– The have more rods (which enable night vision). – They have a structure called the Tapetum Lucidum
This is a reflective surface behind the retina (area including the light sensitive cells) that reflects light back through it (gives the eerie shine at night).
Sight
Sensitivity to Movement
Dogs are better able to detect movement.
Sight
• These differences in visual ability make sense in light of evolutionary theory.
Sight
• These differences in visual ability make sense in light of evolutionary theory.
• Good depth perception and visual acuity are necessary for a primate (from which humans evolved) jumping from tree limb to tree limb.
Sight
• These differences in visual ability make sense in light of evolutionary theory.
• Good depth perception and visual acuity are necessary for a primate (from which humans evolved) jumping from tree limb to tree limb.
• Good colour vision enabled this primate to choose the ripest and most nutritious fruit.
Sight
• These differences in visual ability make sense in light of evolutionary theory.
• Good depth perception and visual acuity are necessary for a primate (from which humans evolved) jumping from tree limb to tree limb.
• Good colour vision enabled this primate to choose the ripest and most nutritious fruit.
• The canine, on the other hand, is well adapted as a nocturnal hunter of camouflaged prey.
Hearing
Hearing
• Hearing. Dogs have an incredible hearing ability.
Hearing
• Hearing. Dogs have an incredible hearing ability.
• In fact it is their second most developed sense, next to smell.
Frequency range
Human
64Hz………………..20KHz
Frequency range
Human
64Hz………………..20KHz
Dog
67Hz…………………………………..45KHz
Hearing
• There are many nerves in the pinna of the ear, including the vagus nerve, which slows the heart.
Hearing
• There are many nerves in the pinna of the ear, including the vagus nerve, which slows the heart.
• Perhaps the basis of 'ear work' in Ttouch.
Touch
Touch
• Dogs have the largest concentration of touch sensors on the pads of the paws, thus they are very sensitive to textural changes on the ground or floor
Touch
• Dogs have the largest concentration of touch sensors on the pads of the paws, thus they are very sensitive to textural changes on the ground or floor
• This textural sensitivity is used in some elements of Groundwork (Ttouch) that help a dog to concentrate and focus.
Smell
Smell
• The dog's brain in large part is dedicated to smell.
Smell
• Depending on the breed a dog will have anything from 125 million to 220 million scent receptors in the brain
Smell
• Depending on the breed a dog will have anything from 125 million to 220 million scent receptors in the brain
• compared to humans who have 5 million
Smell
• Its nasal passages are arranged to allow a greater volume of air to be drawn over the sensitive lining
Smell
• Besides that dogs have sensory cells in their noses that respond to chemicals in the air
Smell
• Besides that dogs have sensory cells in their noses that respond to chemicals in the air
• This vomeronasal organ is similar to a snake’s Jacobson organ
Smell
• Research has recently shown that dogs can reliably detect 6 parts in a trillion
Smell
• Research has recently shown that dogs can reliably detect 6 parts in a trillion
• 100% success for 6 parts in a trillion
Smell
• Research has recently shown that dogs can reliably detect 6 parts in a trillion
• 100% success for 6 parts in a trillion
• 98% success for 2 parts in a trillion
That’s the equivalent of us tasting one teaspoon of sugar in
a million cups of tea!!!!
Taste
Taste
• A dog's taste receptors are almost identical to ours, their taste buds on the tongue can easily identify salt, sweet, sour, bitter.
Taste
• A dog's taste receptors are almost identical to ours, their taste buds on the tongue can easily identify salt, sweet, sour, bitter.
• However the fact that their sense of smell is so superior to ours then we can assume this will, in turn, have an enhancing effect on their sense of taste.
Thank you!