Most people are aware that their dog's senses of hearing and smell are keener than those of humans. Not as commonly understood, though, is the dog's deficiencies in some sensory processes. Whether this leads to problems often depends on the way people interact with the dog. The following information helps explain many canine behaviorisms, and canine reactions that owners don't understand and/or respond to inappropriately when it comes to a dog's visual perception, which create problems or diminish the positive quality of their relationships.

Dogs don't recognize details within an outline, such as noses, eyes, etc., on a human face, but are fairly keen at perceiving outlines. In a Pavlovian experiment they were trained to discriminate between perfect circles and egg-shaped outlines. They performed nicely. But, when the ellipse was gradually rounded until it was 8/9ths of a circle, the dogs failed to recognize the difference, a task most people perceive easily. If repeatedly asked to do this, the dog lost all its previously learned responses, even to the big differences between circles and ellipses. Many dogs became neurotic and had to be retired to kennels for a rehabilitation program of rest. This experiment shows the dog's extreme sensitivity to visually perceived stimuli when they suddenly produce inconsistent feedback.

In a real-life, the owner's hands usually signal positive treatment, such as petting. When the same hands inflict punishment or pain, the dog usually displays a momentary, often subtle, ambivalent behavior, vacillating between affectionate and defensive responses. During initial interviews with clients, this reaction is clearly seen in dogs that have been punished by hand, so to speak. Further, when strangers reach to pet these dogs, the actions may trigger a full expression of submission or aggression, depending on the nervous makeup of the dog and its environmental history.

Most owners are not aware that their puppy's vision does not reach maturity until about 4 months of age. Until then, things appear in various degrees of fuzziness, which makes visual identification of objects and individuals difficult. This can cause some pups to bark or growl at family members. If punished, the pups become confused and the seeds are sewn for problems such as submissive wetting and biting.

Imperfect ability to distinguish various shapes may explain why some dogs, in dim lighting, become unnerved, growl at or shy away from their owners. Though they can virtually "see in the dark" as compared with people, their poor ability to distinguish shapes may be impaired in reduced light. So, when they arc approached in low light levels by the owner, they may growl. Rather than simply clear up the mystery by speaking the dog's name, many owners punish or back away from the pet, reinforcing the behavior. From that point, the problem usually escalates and the relationship between owner and dog degenerates.