by Stanley D. Korfmacher M.D.
Assembly Room, A. K. Smiley Public Library
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.
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.
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
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."
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
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
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
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
"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
"We are alone, absolutely alone on this chance planet; and amid all forms of life
that surround us, not one excepting the dog, has made an alliance with us"
Maurice Maeterlinck 4
"If you eliminate smoking and gambling, you will be amazed to find that almost all
An Englishman's pleasures can be, and mostly are, shared by his dog."
George Bernard Shaw 12
"We are grateful for the very existence of dogs, and I like to think that they
feel the same way about us. Both species have a lot to be grateful for. It is one of the
greatest miracles of nature that we have come together in love and friendship in a way
that no other two species ever have."
Jeffrey Masson 9
I don't know if dogs go to Heaven, but if they don't I want to go wherever they
Will Rogers (on a large sign in the exhibit Dogs-Wolf, Myth, Hero and Friend at the
Natural History Museum of Los Angeles County Oct. 2002-Jan. 2003)