Facts about Dog Sight, Sound and Smell

DOG SIGHT
All dogs are born bund and deaf but both ears and eyes begin to open between roughly the ninth and fourteenth days. Although head shapes vary considerably, eyes are always relatively widely spaced, providing good lateral vision, enabling the dog to see even slight movement through the corner of the eyes, much more easily than can a human. Conversely, dogs cannot adjust their focal length as easily as humans. Dogs' eyes are flatter than those of humans, and more sensitive to light and movement. Via the optic nerve the retina sends information to the brain and, hidden by the lower lid, is the nictitating membrane or 'third eyelid' which sweeps across the eye to keep it clean. To keep the eye moist, tears produced by the lachrymal glands and their ducts flow into the nasal cavity.

DOG SOUND
Dogs' ears are especially sensitive to sound, capable of hearing sound four times further away than a human can. They are also able to locate the source of I sound incredibly quickly, at six-hundredths of a second. Sound is captured by the outer ear and funneled down via the ear canal into the ear drum where vibrations stimulate the middle ear to amplify and transmit sound. Part of the inner ear then converts sound into signals which are sent to the brain. The ears of dogs are incredibly varied in shape, largely dependent upon function, and all are very mobile with the ability to scan for sound. One often sees a breed such as a Whippet moving the ears into the most extraordinary positions in an attempt to hear even better. Often a long ear gives protection and is found especially on dogs which go to ground, while long ears can also sweep up scent, helping in scent detection.
        
DOG SCENT
In any breed, smell is a dog's most advanced sense, and there is even a sex-scenting organ in the roof of the mouth transmitting information to that part of the brain which relates to emotional behavior. Helped by moisture on the nose, scent is captured on this major organ of smell, passing then to the nasal membranes, which detect even the smallest scent. Along the nasal membrane are sensory cells, which convert the scent to chemical messages, interpreted within the brain. To bring the dog's acute sense of smell into perspective, whilst a human has around five million scent receptors in the nasal folds, a dog has about 200 million.         

BODY LANGUAGE OF DOG
Although dogs utter sounds they do not have the speech ability of humans and so, coupled with the noises they make such as barking, growling and whining, they use body language to better convey their mood and feelings. Much of their body language is learned from the dam, and the youngsters practice on their siblings from a very early age. Puppy play looks comical and can sometimes appear frightemngly over-boisterous but at this time important lessons are being learned and put into use. Even in a young litter of puppies a careful observer can distinguish which members are dominant and which more submissive. Usually this strength of character will continue into adulthood, so a that a dominant dog will need more human control and a less confident one more encouragement.

INSTINCTIVE BODY LANGUAGE OF DOG
A puppy jumping up to lick a mother's mouth prompting the dam to regurgitate what she has eaten to produce food, a natural instinct in the wild and one which is carried through to adulthood in dogs' behavior with humans.

Puppies and older dogs show power by stalking others, the hindquarters slightly raised, the ears erect. They stare at another dog or stand over the more submissive individual, possibly even baring the teeth. The less dominant of the two will try to avoid eye contact, may press the tail between the legs and flatten the ears. This dog will probably take up the posture of lying on one side, ears held back and lips retracted to what is often termed a 'smile'. Lying on the side, or even the back, exposes the stomach and genitals, again indicating submission. A puppy may even urinate slightly in the process. Of course, there are many intermediate stages of communication, each important in its own way.

Those who keep more than one dog will usually know which is the pack leader, but the leader may change, often as a dominant dog grows old or a strong puppy matures. For this reason, it is always important for the owner to keep control of the situation so that no unpleasant fights ensue. In a successful canine household, the human should always be the supremely dominant party for only if this is the case will a dog respect the owner and abide by house rules.