A dog's paws contain nerve endings that can help it navigate its movements. A dog's muzzle is rich in nerve endigns and the nose serves as an olfactory and tactile, exploratory function.
Dogs do see colors but not as vivid as humans.They see yellow and blue well but not red and orange as well.They are skilled at picking up on movement, even in dim lighting.
The area of a dog's brain dedicated to smell is 40 times as large as a human's. They have hundreds of millions of scent receptors in their noses.Humans, a mere 400. And, dogs smell while they breath continuously, unlike humans who smell only on the inhale.