Introduction

    This paper is a compilation and distillation of the work of many others, interspersed with my own opinions and feelings. My wife and I and our four children have lived with multiple dogs most of our lives. For me alone this has amounted to about 150 human-dog years! I feel that this, plus my medical education, allows me to have an opinion or two.

    In addition to my childhood dogs, my family has included seven generations of purebred dachshunds, the last one Poppy, still with us at a vigorous 15 years; Smokey, a fine black Lab who was with us 17 years and Pepper, his daughter by the German Shorthair down the street; several rescued mutts, large and small, two of which are current members. Buster is a 10 year old Doberman I found as a young pup near the gate of the California Street dump and Sasha, a young terrier mix obtained from BARC a year ago. She has been a great source of amusement for Buster and for us.

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A DOG'S LIFE

The Origin and Evolution of Dogs

    Dogs have been a part of human life for at least fifteen thousand years and possibly much longer. Recent genetic studies reported in the journal Science in November 2002 confirmed reports of earlier research indicating that all of the breeds of dogs today (nearly 400) and the wild gray wolf are virtually identical genetically. By analyzing minute genetic differences in canine DNA from around the world (654 dogs and 38 Eurasian wolves) it was determined that all existing domesticated canines descended from only five female wolves in east Asia 15,000 years ago probably in present day China. From there dogs quickly spread to Europe, and to Australia over the land bridge after the last Ice Age with the Aborigines, and to North and South America over the Bering Strait with early native Americans 12,000 years ago. A separate study ruled out independent evolution from American wolves; DNA from 37 dog remains in pre-Columbian Mexico, Peru, and Bolivia and additional ancient dog remains from Alaska showed that dogs of our Western Hemisphere - ancient and modern - owe their origins to the same East Asian wolves. 1

    What brought wolves and humans together? The East Asian wolf is smaller and probably easier to domesticate than other wolves. Humans and gray wolves, both pack animals, have shared habitats and hunting grounds for millennia. Humans began to establish settlements about 15,000 years ago. For wolves, scavenging the resulting refuse might have been good survival strategy. Cooperative hunting is another possibility.

    Over many generations, selective breeding gave rise to breeds that were very different in appearance and capabilities and demeanor. The few breeds considered native to North America vary from the large, heavy coated Eskimo dog to the small Mexican hairless. They have been in North America for over 2000 years and they are virtually indistinguishable genetically from Eurasian dogs. The unique strains in ancient remains in Mexico. Peru and Bolivia are nowhere to be found today. Smithsonian geneticist Jennifer Leonard speculates that the conquistadors may have purposefully killed off the dogs, and/or the new European dogs may have had more appeal. 1

    The enormous variation of dogs, with hundred-fold variation in weight between St. Bernard and Yorkshire terrier and ten-fold height difference between Great Dane and Yorkie makes it hard to realize they are the same species. Any breed can interbreed with any other and produce fertile offspring, though some combinations would require artificial insemination! The same is true for domestic dogs and wild wolves; they too produce fertile offspring. 3

    In recent years, field observations of packs of wild wolves, long thought impossible because wolves do not tolerate close observation by humans, has been made possible by improved photographic and video equipment of dedicated animal researchers. These studies have shown that far from being a savage beast, it is a species with impressive social organization
involving a great deal of restraint, control by order of rank and mutual aid. There is healthy competition balanced by active cooperation in hunting, defense of the pack, when breeding, and in feeding and caring for the young. There is very little fighting within each social group. There is certainly no shame in dogs having originated from wolves.

    Quoting from Peter Messent: "Once the wolf has been tamed, specialist breeds of what was by then a dog seem to have developed quite quickly. Egyptian pottery, 7500 years old, show a dog of the Greyhound/Saluki type which had almost certainly been bred to chase game in the desert. Greyhounds and Salukis therefore have the longest known pedigrees of all modern breeds, although they have undoubtedly changed since their early days in the desert.

    "All the evidence suggests that the ancient Egyptians cared as much for their dogs as most modern civilizations, if not more so. Many of their towns had special dog graveyards, and Anubis, the jackal-headed god of death was the object of devout worship and reverence.

    "Frescoes, bronzes, carvings and written references reveal that by 2000 BC the Egyptians had mastered the principles of breeding and developed it to a high level of sophistication; several breeds are depicted, and these include a toy dog, similar to a Maltese, bred almost certainly as a pet and not for any practical purpose.

    "The Romans had separate descriptive names for house dogs, shepherd dogs, sporting dogs, war dogs, dogs which fought in arenas, dogs which hunted by scent and those which hunted by sight." 11

    In China, the Pekingese were bred in the T'ang dynasty in the 7th century and were closely associated with the emperors.

    Today, we have over four hundred recognized breeds of dogs plus uncountable varieties of mutts! Many of these dogs were bred for specific purposes including hunting, tracking, guard duty, racing, protection, war, hauling carts and sleds and barges, companionship and show. More recently certain breeds have proved useful for persons with impaired or nonexistent vision or hearing, for sniffing out drugs or bombs, as police dogs and rescue dogs, and even as actors in movies and television. And we must not forget the thousands of laboratory dogs who have been sacrificed to teach anatomy, physiology and surgery and to test drugs and new surgical techniques. Remember too that the first astronaut was a little Russian dog.

The Senses of Dogs

    Dogs possess remarkable sensory equipment which, along with their intelligence and trainability has allowed mankind to benefit from dogs in a great many ways.

    First, vision. Nearly all dogs were felt to be farsighted and colorblind until recent years. Hunting dogs do have excellent distant vision, but some breeds have a significant incidence of nearsightedness. About a quarter of Rottweilers were found to have two diopters of myopia, which is quite disabling to humans when uncorrected. Dogs have great preponderance of rods over cones in the retina; this gives them good night vision and motion detection. They also have a light-reflecting layer behind the retina, the tapetum lucidum, which, as in cats and nocturnal animals enhances night vision. The paucity of cones limits color vision to two areas of the visible spectrum, red-yellow-green and blue-violet. Thus red, orange and yellow-green all look much the same to a dog but can be distinguished from blue or violet. The colors between green and blue are probably seen as gray. The field of vision of dogs is much greater than that of humans, 250 to 270 degrees vs. 170 to 180 degrees. They have binocular vision but only half the width of humans. 3

    Turning to the sense of smell, the canine advantage is truly significant; dogs have 220 million olfactory cells vs. five million in humans. Depending on the odor or chemical tested, dog's detection capability is never under a hundred times better, and is usually thousands of times better, and ranges upwards to one million times better. For example, one of a set of glass slides is touched briefly by a single fingertip; the slides are put away for six weeks. When they are brought out again the test dog is able to find the one that had been touched.

   Blood hounds can follow a trail as much as four days old and can track a human subject for up to one hundred miles. The scent from human feet is so strong to a dog that it can identify individual odors even in areas where many feet have trod and where shoes have been worn by all concerned.3 Other tasks for canine noses include hunting game, hunting truffles, drug detection, bomb detection, finding lost people and buried victims of avalanches, landslides, tornadoes, earthquakes and explosions. 3

    Let us next consider the hearing of dogs. With low pitched sounds, humans hear as well or better than dogs; dogs cannot hear the lowest octave of the piano, although some of them certainly react to thunder! They probably feel it more than hear it, much as humans feel the deepest pedal notes of a great organ in the octave below the piano. Dogs, however, hear two to three octaves higher than we do, up to 100,000 cycles per second. This enables them to hear the ultrasonic sounds of birds, mice, and bats. This probably explains how dogs can identify the approach of their owner's car and run to the front door when the car is still blocks away.

    Other senses may be more highly developed in dogs as well, such as sensitivity to vibration, and to changes in barometric pressure which have enabled some dogs to apparently be aware of impending storms, flash floods, tornados and earthquakes. Dogs also have demonstrated remarkable sense of geographic place enabling some to return to distant homes over long time periods.

Canine Communication

    Dogs use all of their senses to communicate with each other and most of them to communicate with us. They have a rich body language utilizing eyes, ear position, head position, lip positions, nose wrinkling, body position, tail position and movement and hair erection on the back. Much of this has to do with dominance or submission but lip position is not all snarling. When the lips are drawn back in a smile of sorts it means the dog is happy, friendly and playful. Licking expresses love or gratitude. It is also used by puppies to ask for food and by adult dogs, along with a crawling position, to come close to dominant dogs without risking attack. Invitations to play also include nose-nudging, beckoning with downward swipes of one front paw in the air while sitting and bringing play objects which are dropped on the ground or floor near the companion while the dog then lies down with the "offering" between its front feet, ready to snatch it and run off to be chased if the canine or human companion shows an interest in the object.

    Vocalization in dogs also conveys a wide range of meanings. Stanley Corren 4 offers the following compilations: Barks, continuous, rapid midrange; "Help! Someone is coming into our territory." Continuous slower and low pitch: "The danger is very close". Strings of three or four barks midrange: "There may be a problem or intruder, pack leader should go see." Prolonged barking: "I need companionship" (a response to confinement or being left alone for long periods). One or two short midrange barks: "Hello there!" Single bark, low to midrange: "Stop that!" ( mother dog disciplining a pup or dog disturbed from sleep, etc.) Short, sharp bark, higher pitch: "What's this?" If repeated two or three times,"Come look at this!" Single bark, midrange: "Come here" or "I need to go out" or "Look at me". Single yelp, a very short high pitched bark: "Ouch"! Series of yelps: Severe pain or fear. The yip-yip-yip howl: "I'm abandoned and lonely" Stutter bark "ar-ruff: Let's play". Rising barks- series of barks in which the pitch rises from mid to high within each bark occurs during vigorous play: "This is fun!" or excitement such as digging or running while hunting. Moaning "ar-owl-wow-wowl" is a sound of pleasure and excitement when something the dog really likes is about to happen.

Growls: Soft, low pitched growling: "Back off!" Low pitched growl-bark: "This is your last warning". Midrange growl-bark: "I don't want to fight but I'll defend myself". Undulating: low to high midrange with semi-bark: "I'm unsure/or frightened".-dog may either fight or run. Noisy growl with teeth hidden: "This is a good game-I'm having fun". (eg. tug-of-war.)
Whines: Soft whimpering; "I'm scared (eg vet's office). Louder, longer whine: "I want" (attention, food or hurry and put on the leash)

Sighs: A sigh when the dog is lying down with head on forepaws and eyes half closed means "I'm contented". A sigh with eyes open means "I'm disappointed," usually when something anticipated has not materialized.
Howling: "I'm in my territory". Dogs do not howl nearly as much as wolves, for whom group howling seems to be an enjoyable social event.

Baying: Characteristic of hunting hounds, means "All together now, let's go get him!"

Dogs also have a rich body language.

Eyes: Staring eye to eye is a sign of dominance or a challenge for dominance. Eyes turned to avoid direct eye contact are a sign of submission.

Tail: Tail high; "I'm confident" or "I'm the dominant dog." Tail below the horizontal: "I'm relaxed." Tail down, legs straight: "I'm not feeling well" or I'm depressed". Tail down, legs bent, back sloping down: The dog is unsure or insecure. Tail between legs: "I'm frightened (or ashamed), don't hurt me"! Tail with bristling hair: "I'm ready to fight". Rapid tail wagging equals excitement. Slight tail wag: "I see you looking at me - you like me, don't you?" Broad tail wag: "I like you" or "I'm pleased". During play, it is reassurance that the barking and growling is all in fun. Slow tail wagging with tail half down: "I don't understand what we are doing."

Ears: Erect, forward: Dog is alert and interested. Same with tilted head: "Very interesting but this is new to me". Ears pulled back and spread sideways: "I don't like this; I'm ready to fight or run." Ears pulled back flat against head: "I'm frightened."
Mouth: Smile: Mouth relaxed, slightly open. Yawn: unlike humans, in dogs, a sign of tension and anxiety. Lips curled: "You are annoying me". Lips curled and major teeth evident: "If you keep on, I may bite." Lips curled, all teeth and front gums exposed, nose wrinkled, hair on back bristling means violent attack imminent. (If you are confronted with this do not turn and run. Cast your eyes down, open your mouth and back away slowly.)

Body: The play-bow: Dog lowers head, extends front legs and keeps up: "Let's play!" Stiff-legged movements: Asserts authority and dominance. The roll-over: A sign of submission (or inviting a belly rub.) Paw on knee or head slide under hand or elbow: "Let's do something."

        Last, but certainly not least, dogs communicate by smell, a facility which we can barely appreciate. The small anal glands apparently have an odor unique to each individual and this usually transfers to fecal deposits. Marking of territory and possessions with urine also implies unique odor variations. Female odor production during estrus is obviously of great importance. Odors produced by various diseases in both humans and dogs are well known to physicians and are likely to be even more evident to dogs. Wolves have an additional scent gland in the tail which dogs have lost, indicating an even more complex olfactory life.

Intelligence of Dogs

Long ago, and far away, at Carleton College in Minnesota in 1950, I was a nineteen year old sophomore in a sociology class. The professor stated as a fact that dogs were incapable of feeling or displaying emotion of any kind. I challenged him in class and made a few points (and allies) when he had to admit he had never lived with a dog. However, he was adamant in his views. Only later did I realize that he was simply parroting the "party line" of behaviorist psychologists and sociologists who maintained that all animals lack consciousness. Unbelievably, it would be decades before this was discredited by superb animal studies on many species, most done by scientists in other disciplines. In addition to dogs, chimpanzees and gorillas, lions, meerkats, wild African dogs, elephants, dolphins and whales have yielded many of their secrets. In general they have been found to live more complex lives than we had imagined displaying intelligence and resourcefulness, altruistic behavior and emotions.

    Animals communicate in fantastic ways, such as the subsonic rumbles of elephants picked up by elephant feet miles away. We have come to appreciate the diverse languages of animals and also that some of them such as chimpanzees, dogs, dolphins and elephants can understand over a hundred of our words, hand signals or signs and computer symbols for words. Use of language implies cognition or thinking as does complex behavior observed in the wild. Deviations from learned behavior in trained animals in response to unusual circumstances also are good indications of thinking.

    I am sure most dogs lovers would agree that dogs also show self-awareness. Who has not seen a dog displaying shame or chagrin when caught in forbidden behavior or after a poor performance? It is not the same as simple submissive behavior or fear. Who has not seen pride in the hunting dog dropping the duck or pheasant at its master's feet, or a show dog after a good trip around the ring, or a family dog after a good Frisbee catch? It is not the same as simple excitement because it is linked with an accomplishment.

    I believe dogs feel and display many of the same emotions that we do. I also feel that many other animal species are capable of emotion. The book When Elephants Weep: The Emotional Lives of Animals by Jeffrey M. Masson and Susan McCarty is convincing in this regard. (This book is limited to wild animals.)

    So why, for most of the twentieth century, did animal researchers deny animal consciousness and emotions? We have seen that many ancient civilizations respected and revered dogs (and many other animals). Aristotle felt that the intelligence and emotions of dogs and humans differ only in degree. This opinion held sway for centuries. In the thirteenth century Thomas Aquinas established as formal church doctrine that human and animals differ only quantitatively in their mental abilities rather than in the nature of their mental processes. However, accepting that dogs had intelligence and consciousness was tantamount to conceding that also had souls, an unacceptable conclusion to many other Christian scholars. There was also a long Judeo-Christian tradition that dogs were unclean; this persists as an almost universal view throughout the Islamic world to this day. 4

    Then along came Descartes in the 1600's whose mechanistic theories denied animal thought or feelings or even conscious pain perception. Dogs were nailed down by four paws and cut open for observation by men oblivious to their cries of agony. Yet Descartes' views were widely accepted until Darwin and many other scientists in the nineteenth and early twentieth century debated animal mentality.

    The pendulum swung back again with behaviorism in the 1920's and 1930's restricting scientific attention to overly observable behavior, avoiding the mental experiences of animals as unknowable or subjective. This attitude was still common very recently [Colgan (1989) and Yoerg (1991) as quoted by Donald Griffin 5] and scientific journals would refuse to publish data or interpretations supporting animal consciousness.

    As recently as 1990, the philosopher, John Searle wrote: "Few people in cognitive science think that the study of the mind is essentially or in large part a matter of studying conscious phenomena: consciousness is rather a 'problem', a difficulty that functionalist or computationalist theories must somehow deal with…. As recently as a few years ago, if one raised the subject of consciousness in cognitive science discussions, it was generally regarded as a form of bad taste, and graduate students, who are always attuned to the social mores of their disciplines, would roll their eyes at the ceiling and assume expressions of mild disgust." ( As quoted in Griffin p 239 5)

    However, in 1992, Donald Griffin wrote "Numerous articles, review articles, symposia and substantial books led (in the 1980's) to a cognitive revolution in psychology that has largely replaced behaviorism." Yet even these researchers often ignored the question of conscious awareness of the cognitive processes. Griffin feels that this is more philosophical aversion that a lack of scientific tools. In analyzing his colleagues opinions he states; "It is admitted that animals may sometimes experience perceptual consciousness, but that reflective consciousness is a unique human capability… animals may know certain things but they do not know what they know. People can tell what they are thinking about but animals are felt to be incapable of doing so." Even this last bastion has crumbled, as well it should, since it flies in the face of common sense and everyday observance. Dogs of all kinds know and tell us when they are thinking of food or going for a walk, or playing ball, or needing love, reassurance or attention. How could they be unaware of their thoughts when they come into a room with their leash or Frisbee in their mouth without any external input?

    It seems to me that dreams are another aspect of consciousness. The sleep of more than 150 mammalian species has been studied by electroencephalography and only the dolphin seemed never to dream. (Perhaps deep REM sleep in the dreaming state would prevent it from going to the surface to breathe.) There was never any doubt that dogs dream - they move their legs, ears and whiskers, wag their tails, whine, bark, moan and howl in their sleep. REM activity in dogs occupies 36 percent of the total sleep vs 20 percent in teen-aged humans and 13 percent in our old age. 9

    Griffin 5 cites three categories of evidence for conscious thinking by nonhuman animals: 1) "versatile adaptability of behavior to novel challenges"; 2) "physiological signals from the brain that may be correlated with conscious thinking" (to which I would add brain imaging.) and 3) "communicative behavior by which animals sometimes appear to convey to others at least some of their thoughts." He then gives us 250 pages of examples and cites over 600 articles and books in his bibliography, covering a wide range of animal species. These animals engage in cooperative behavior, and build elaborate structures, use tools, communicate with a wide range of sounds and movements, all in their natural habitats. Moving on to animal training, he gives amazing examples of dolphins following complex three to five part commands given by whistle-like sounds or hand signals with a "vocabulary" of at least 35. In addition, each dolphin, wild or tame, has a signature whistle unique to each individual, and dolphins can be trained to imitate a wide variety of whistles. Dolphins also learn tricks by simple observation of other dolphins performing them. In the 1980's two California sea lions were trained to respond correctly to 64 and 190 gestures and combinations (one object plus two modifiers or two objects with one action).

Even more important are the chimpanzee studies by the Gardners at the University of Nevada; they acquired one year old Washoe in 1969 and in three years she learned to use and respond appropriately to eighty-five ASL [American Sign Language] signs. She and several other chimps and a few gorillas and orangutans have since learned to use over a hundred signs each. Washoe also extended the use of signs beyond the trained meaning; the sign she learned to ask that doors be opened she then used to request her human companions to open boxes, drawers, briefcases, picture books and to turn on a water faucet. 5 Later studies have involved symbols on tokens    or a simplified computer keypad; with these, two chimps cooperate on a task, eg one will ask the other to bring the only correct tool from a group of tools which will open a certain box containing food. Strings of symbols make rudimentary sentences. One researcher's star pupil, Sarah, not only could arrange tokens to ask for things but when humans arranged the tokens she could answer simple questions such as "What color is the flower?" 5 None of these symbols resembled the things they stood for.

    Recently reported studies of isolated groups of wild orangutans in Borneo and Sumatra using long term video taping of many common activities revealed new facets of animal intelligence and communication. Not only did each group have different ways of achieving the same goal, but there was excellent evidence that parents and siblings taught these unique activities to the young. This is certainly a big boost for Griffin's third category of evidence for thought. 7

    Another very recent study with dogs and apes also had surprising results and supports the emerging consensus that small genetic variations magnified by selective breeding have resulted in dogs which fit humans like a hand in a glove. I quote the abstract of this study which appeared in Science this very month. 8

    "Dogs are more skillful than the great apes at a number of tasks in which they must read human communicative signals indicating the location of hidden food. In this study we found wolves that were raised by humans do not show these same skills, whereas domestic dog puppies only a few weeks old, even those that have had little human contact, do show these skills. These findings suggest that during the process of domestication, dogs have been selected for a set of social-cognitive abilities that enable them to communicate with humans in unique ways." 8 In this study an experimenter reached toward, gazed at and marked the correct container with a wooden block. Nine out of eleven dogs went to the correct container but only two of eleven chimps. Gazing and pointing alone or with brief tapping on the correct bowl were used for the dog vs. wolf experiment.
    There are hundreds of tales of heroism and altruism in the literature which further support the unique human and canine relationship. 9, 10, 12