The Companion Animal Behaviour Institute (CABI) Certificate in Canine Behaviour Unit 2 Physiology - Canine 1
It is important, when studying animal behaviour, to understand the importance of the animal s physiology as a primary determinant of its behaviour. Animals behave in accordance with the way they are wired to behave. A simple example of this is why cats will sometimes leap onto prey from the branches of a tree, and dogs never do. It is not because dogs can t jump, or leap from heights, nor is it because dogs aren t interested in catching the prey, but rather it is because dogs are physically incapable of climbing trees, and that is inherent to their physiology. Dogs: Sense of Taste: Dog food advertisements often make statements along the lines of rich beef flavour, dogs enjoy the taste of, or your dog will find the taste of irresistible, etc. From this you might conclude that taste is one of the most important senses a dog possesses. Alas, this is not the case. Taste sensitivity depends on the number and type of taste buds an animal has. Humans, for example, possess about 9,000 taste buds, which is nearly 6 times as many as dogs who have only 1,700. Certain taste buds are tuned to certain taste groups. These groups can be broken down into the 4 basic taste types: sweet, salty, sour, and bitter. The taste receptors in dogs respond to sweet, sour and bitter (though they do not have the capacity to taste the range of varieties within these groups), however they are not as sensitive to salt. Humans seek out the salt flavour in our food, and most fast foods and snack foods are highly dosed with it. Dogs on the other hand do not have the same requirement for salt in their diet because of the high sodium content in meat. Dogs are not exclusively carnivorous because they will eat plant material as a supplement to their diet. Though, in the wild, 80% of a dog s diet is meat, they will also eat vegetables and fruits. Cats on the other hand, are true carnivores. Anything other than meat from animals, birds, and fish will be difficult for a cat to digest. 2
Dogs possess sweet taste buds that detect furaneol, which is found in fruits such as pears. Where dogs can often display quite a liking for sweet things, hence the many dog treats on the market such as dog chocolates etc, cats are virtually taste blind for anything sweet and will often show no interest in sweets at all. A warning: In countries where vehicles use antifreeze containing ethylene glycol, it is important to be aware that this chemical activates dog s sweet taste buds. As little as 60 milliliters (2 fl oz) of this sweet tasting ethylene glycol can kill a medium-sized dog. Surveys in the USA indicate that between 10,000 and 30,000 dogs die each year from ethylene glycol poisoning, either from drinking the fluid directly or from walking through it and then licking their paws. The early symptoms of ethylene glycol poisoning are; wobbling/staggering as if drunk, depression, vomiting and diarrhea. Induce vomiting, if possible, and seek veterinary attention urgently as the fatality rate is extremely high. There are antifreezes available that contain the less harmful propylene glycol, and dog owners should be encouraged to use these brands. Dogs have taste buds that are tuned for water (as do cats). This ability to taste water is important to all carnivorous animals because the digestion of meat requires it. Dogs seem to get pleasure out of drinking water and will often drink copious quantities of it. Taste preferences: Dogs tend to prefer meats over vegetables. Surveys show that they also prefer beef and pork over lamb, chicken and horsemeat, however this is also connected to their ability to smell the food. They also prefer moist food over dry food and warm food over cold food, because the scents emitted by the food are greater if moist and warm. Taste preference however, is a luxury that dogs will often ignore, especially if other dogs are around to compete for the food. Most dogs do not eat delicately, instead they tend to gulp their food down without stopping to evaluate the taste. This is how pack predators eat; quickly, so that the food is safely in their bellies before the others in the pack can come along to steal it. Cats, on the other hand, are solitary hunters and because they don t have the pressures of the pack to consider, will tend to eat more deliberately and delicately. 3
Hearing: A dog's sense of hearing plays an important role within their environment. Dogs have far greater hearing than we humans. In addition to what the human ear can hear, dogs can detect fainter sounds from greater distances and on much higher frequencies. The human ear has a frequency upper limit of about 20,000 cycles, while the dog s range can be as high as 40,000 cycles. This means that dogs have a highly developed sense of hearing that can hear a wide range of sounds. The frequencies that dogs can perceive and hear are over twice that of humans and they can pick up and distinguish sounds at approximately four times the range of humans. They also have the ability to pin point the exact origin of the sound, as well as discriminate between sounds and make an accurate interpretation of the sound. As dog's ears are able to move in different directions, it is easier for dogs to pinpoint the exact location of a sound's origin. This means that a sound detectable by human hearing at 20 metres, a dog can detect, pinpoint and interpret at 80 metres. This is achieved by the dogs specially designed inner ears that allow them to operate like radars. Breeds with pricked (erect) ears have a better ability to localize and detect sounds than those with floppy ears. Floppy ears hang down and tend to block some of the incoming sound, and they do not rotate as effectively either. Not only do dogs hear the sounds but they also perceive the height and depth of the sounds they hear. Dogs also have the ability to hear ultra high frequencies that humans cannot. Many professional dog handlers and trainers use this ability to their advantage by teaching their dogs to respond to different commands given on whistles. These produce such ultra high frequency sounds that they are inaudible to humans. Because of this it is quite possible that when a dog is barking for seemingly no reason, it is because they are responding to a sound they can hear at an ultra high frequency, which we are not able to detect. Dogs have the ability to pick out and isolate a single sound from a cacophony of sounds and noises that human ears perceive as a jumbled mess. This enables 4
them to quickly go on the alert to prepare for the possibility of a threat, or conversely become excited and happy at the prospect of an enjoyable experience. This ability has recently been used in some regions of Central and South America with vampire bats. These bats, which attack and feed in groups of up to forty, use sonar that depends on high-pitched screeches in the range of 40,000 to 100,000 Hz to fly and locate their prey. This is a much higher frequency than humans and even cattle can hear, which means the bats can safely land on cattle and people in the dead of night to feed on their blood. The problems associated with infected open wounds and blood loss in cattle and the transmission of rabies to humans has resulted in a number of deaths. Dogs in these regions are rarely ever attacked by vampire bats, and at first it was thought that this was because they had a protective covering of fur. This has now been proven not to be the case. The reason dogs avoid being attacked is because they can hear components of the bat s high-pitched screech and therefore avoid them. Vampire bats do not like to attack moving targets. This has resulted in dogs being trained to stand guard on cattle and people, listening for vampire bat sonar and when they detect bats approaching they bark and cause the cattle to move or the people to waken. Dogs are also very sensitive to complete silence, taking this as a warning sign of impending threat. This sensitivity to silence is found in many wild animals as well. Because dogs clearly distinguish different pitches in sound, the tone of a person s voice is often more significant to a dog than the words themselves. Since dogs respond more quickly to sharp sounds, you will find it easier to get a puppy to come when called if you reinforce your voice command with a whistle or handclap. Instructions such as STOP should always be sharper in tone than ordinary communications. Any unexpected or unusual voice will alert a dog. Its immediate reaction is to face the direction of the sound and then approach warily. Dogs perceive sound by feeling as well as through their ears. They react to vibrations of airplanes and earthquakes long before we are aware of them. Continued sharp or percussive noises can cause real suffering for a dog s sensitive hearing. In some cases a dog may seem to have a pathological fear of 5
thunderstorms or explosives, when the real reason for its cringing behaviour could be simply physical pain. Hearing Loss: Congenital hearing loss is mostly due to genetic factors. A study involving 17,000 dogs confirmed that coat colour and other aspects of the dog s pigmentation are associated with congenital deafness. The genetic defect associated with deafness is closely linked with the genes that produce white, roan (a coat pattern in which the base colour - often red - is mixed with white hairs and looks lightened or mottled), and piebald (spotted, especially black and white) colours. The classic example of a piebald dog is the Dalmatian. 22% of this breed are deaf in one ear, and 8% are deaf in both ears, which amounts to a very high 30% born with some form of hearing deficiency. In some breeds white, roan and piebald genes are found in individuals, rather than in the breed as a whole. For example, the bull terrier can either be white or have prominent colour patches. Among white bull terriers, the rate of congenital deafness is 20%, while for those with colour patches it is around 1%. The gene that causes whiteness in dogs also tends to make it more likely that the dog will be blue-eyed. Since this gene is linked with deafness, we would expect blue-eyed Dalmatians to most likely be deaf. This predication is true, with 51% of all blue-eyed Dalmatians being totally deaf in at least one ear. Vision: A number of factors are involved in vision; it includes not only the perception of light and motion, but also visual perspective, visual field of view, depth perception, visual acuity, and the perception of colour and form. The canine visual system is designed to operate well in low light conditions, while human vision operates best in bright light. Dogs are capable of functioning under a wide range of lighting conditions, as are humans, but their adaptation to low light conditions enhances their ability to function well as hunters. It is thought that dogs are able to see in light conditions up to three times lower than humans can. 6
Humans and canines both have rods and cones present in their retinas, but the relative amount of each is very different. Rods and cones are the photoreceptors present in the retina and the dog s eye is composed primarily of rod photoreceptors, while the human retina is composed primarily of cone photoreceptors. Rods function better in dim light, while cones are used for colour vision and require bright light. Because of the lower number of cone photoreceptors in a dog s eye, dogs are red-green colour blind. The greater number of rod photoreceptors allows them to see a brighter, but less colour-detailed world when compared to humans. Dogs do possess and use color vision, but not to the same degree that humans do. Visual field of view is the area seen by an eye when it is fixed on one point straight ahead. In dogs, this varies between breeds because of the differences in the shape of the skull, placement of the eyes in the skull, and the shape and size of the nose etc. In the average dog, the total field of view is approximately 240 to 250 degrees, which is 60 to 70 degrees greater than the normal human's field of view (180 degrees). See figure below. 7
Dogs see more of the world around them, but distance is not judged quite as well. The ability to determine depth (distance) depends principally upon binocular vision (having eyes that are set in the front of the head, as distinct from animals that have their eyes placed in the sides of their head, like cows, sheep, parrots etc). The degree of binocular vision present in dogs is determined by the area of visual overlap, which is approximately 30 to 60 degrees (though this may vary somewhat between breeds), which is much less than in humans, who have approximately 140 degrees of binocular overlap. (See figure above) Dogs can detect an object in motion at up to 900 metres, but are only able to detect the same object when stationary at between 500 and 600 metres. Visual acuity is the ability to see the fine details of an object separately and clearly. Visual acuity depends on three factors: a) optical properties of the eye, b) retinal detection and processing of the image, and c) proper interpretation of the images by higher centres in the brain. A variety of studies have been done, using a number of different methodologies, to estimate the visual acuity of dogs. We can assume from these studies that the normal dog has a visual acuity of approximately 20/75. A human with good eyesight is said to have 20/20 vision. What does this mean? The standard measurement for visual acuity has been set at 20 feet (or 6 metres). A person is said to have 20/20 vision (or 6/6 vision in metric terms) if they can see an object normally, at a distance of 20 feet, what the average person with normal eyesight can also see clearly at 20 feet. So, if dogs have 20/75 vision it means that they need to be 20 feet from an object to see clearly what a human with normal eyesight can see at a distance of 75 feet from the object. In contrast to this, a hawk for example, has 200/20 vision. This means that it can see an object clearly at a distance of 200 feet that a human can only see clearly at a distance of 20 feet. 8
Again, this less acute vision in dogs is a trade-off for improved vision in dim light, and their life style does not require visual distinction (visual acuity) of fine details in the same way that ours does. Although a dog s vision may be considered inferior to ours in such things as the degree of binocular overlap, colour perception, depth perception, and visual acuity, a dog s vision is superior to ours in the areas that are important for them to function effectively within their environment, such as their ability to see well in low light conditions, wide field of view, ability to differentiate shades of grey on the colour spectrum, and their ability to detect motion. Dogs also differ from humans in the way they use their sense of sight. Dogs use vision mostly to confirm what they already know. For example, a dog will hear the familiar footsteps of its owner approaching the front door (and it can certainly detect its owner s familiar odour even through the closed door), so when the owner actually enters, the dog s vision simply confirms what it already knew. The same thing happens when a hunting dog recognizes the familiar scent of a rabbit. If a dog is on the trail of the rabbit and gets close enough to where it is hiding to actually see it, the dog s vision confirms what it already knows, unlike humans, where coming across a rabbit s hiding place and seeing it dart away, will almost always be a surprise. Once the rabbit is in motion, the dog s eyes are useful information gathering devices. However if it stops motionless, the dog will have trouble seeing it and will have to rely on its sense of smell to describe where the rabbit is. Because a dog s eyes are generally not its primary sensing organ, the information it gathers about the world in which it lives is not primarily visual. Human s minds are mostly filled with visual images. A dog s mind is mostly filled with sound and scent images. Sense of Smell: The scientific term for the process of smelling is olfaction. This is a dog s primary sense. A dog s sense of smell (olfaction) is said to be a thousand times more sensitive than that of humans. Though this varies to some degree between breeds, a dog can have more than 220 million olfactory receptors in its nose, while humans have only 5 million. 9
The olfactory receptor cells in a dog s nose extend throughout the entire nasal cavity, and the olfactory portion of the nasal mucous membrane contains a rich supply of olfactory nerves that connect with the highly developed olfactory lobe in the dog's brain. In addition to this, dogs have an olfactory chamber called the vomeronasal organ (also known as Jacobson's organ), which consists of a pair of elongated, fluid-filled sacs that open into either the mouth or the nose. It is located above the roof of the mouth and behind the upper incisors. The olfactory receptors in the nasal cavity are anatomically distinct from those in the vomeronasal organ Here s how it all works The moisture secreted by mucous glands in the nasal cavity (that s why a dog s nose is normally cool and moist) captures and dissolves molecules in the air and brings them into contact with the specialized olfactory membrane inside the nose. Dogs use sniffing to maximize detection of odours. Sniffing is actually a disruption of the normal breathing pattern and is accomplished through a series of rapid, short inhalations and exhalations. The nasal pocket permits the odor molecules that are unrecognizable in a single sniff to accumulate and interact with olfactory receptors. Odour molecules in the olfactory membrane of the nasal cavity are absorbed into the mucous layer. This interaction generates nerve impulses that are transmitted by the olfactory nerves to the dog s brain, which has a welldeveloped olfactory lobe. This allows the dog to recognize a scent and follow a trail. Olfactory receptor cells in the vomeronasal organ also send impulses to the region of the brain s hypothalamus associated with sexual and social behaviours. This organ is also believed to be important in the detection of pheromones (body scents). As you may have guessed, because the olfactory receptor cells in a dog s nose extend throughout the entire nasal cavity, the size of the nasal cavity, or in other words the length of the dog s nose, is an important consideration. Breeds of dogs with larger noses will have more smell receptors and hence greater scenting ability. For example, the dachshund has about 125 million olfactory receptor cells, while the fox terrier has 147 million and the German shepherd has about 225 million. 10
Some dogs, in particular the scent hounds, have noses that are designed to be very wide and deep in order to pack the greatest number of odour-analysing receptor cells into the available space even if the dog is not very large. The beagle, for example, though small in comparison, has the same 225 million scent receptor cells as the German shepherd, which is twice its size. The grand champion of scenting however, is the bloodhound, which possesses around 300 million olfactory receptors in its nose. Dogs have added brain capacity devoted to smell, and they are about 50 times more scent sensitive than humans, yet most people do not appreciate just how great the difference is. Dogs are, of course, specially tuned for animal-related odours because they are predators. If we test the human sensitivity to butyric acid, a component of sweat, we find that we can detect its odour at a reasonably low concentration of about one five-millionth of a gram evaporated into a cube of air one metre square. Now that may sound impressive, but consider that if we dissolve the same amount of butyric acid in 1 million litres (250,000 gallons) of water, the dog would still be capable of detecting it. If we take one gram of butyric acid and let it evaporate in a volume of air large enough to fill a ten-story building, a human would just barely be able to smell it. If we evaporate the same gram of butyric acid in a volume of air large enough to fill an area 350 kilometres square (135 square miles) by 92 metres high (300 feet), a dog would be able to smell it. Sniffing Vs Breathing; Dogs work more actively than humans to gather scents. They don t let odours casually drift into the nose like we do, but instead they gather odours from the environment, and they possess specialized equipment for accomplishing this task. Dogs can move (or wiggle) their nostrils independently in order to assess which direction a scent is coming from. Dogs also utilize a special sniffing ability that is different from their normal breathing. When a dog pushes its nose in the direction of a scent, it is actively interrupting its normal breathing process and replacing it with the sniffing process. As a dog sniffs, the air passes over a bony shelf-like structure in the nasal cavity that is designed to trap the air and protect it from being expelled when the dog exhales. This allows the scent molecules in the air to accumulate so they can be identified. When a dog breathes normally (pants), the air passes through the 11
nasal passages below this shelf-like structure and continues on down to the lungs. In extremely hot weather, a dog s ability to detect and interpret scent can diminish noticeably. This is because when a dog is hot, it needs to pant to increase evaporation of the moisture in its mouth and on its tongue, and this provides relief from the heat. The more a dog pants, the more efficient the cooling affect, however the more a dog pants the less it is able to engage the sniffing process and thus the less reliable is its ability to detect scents in the air. By the way, many people believe that a dog perspires through its mouth, however this is not true. Dogs have sweat glands only on the pads of their paws (humans have sweat glands distributed over their entire body). Sometimes, when a dog is highly stressed or overheated, it may leave wet paw prints. Can the shape of a dog s ears impact on its ability to detect scents? There is some evidence to support the contention that floppy eared dogs make better scent hounds than dogs that have pricked ears. In an experiment conducted in the 1960s a mouse was released into a fenced off field approximately one acre (4000 sq metres) in size. The mouse immediately ran away to hide as far from the release site as it could get. A short time later, beagles (floppy ears) were released into the area and it took them about one minute, on average, to track and locate the mouse. Fox terriers (floppy ears) took about 15 minutes to locate the mouse. However when Scottish terriers (pricked ears) were released into the field, they completely failed to locate the mouse. The Scotties did not even try to track, and in one incident one of the dogs accidentally stepped on the mouse without noticing it. Though there is much contention on this issue, some dog breeders believe that floppy eared dogs make the best scent hounds because as the dog moves its head back and forth along a track, their ears move and flap and this movement pushes the air from around the face down to the ground and provides the dog with more scent molecules. Pheromones; The primary senses used by humans to detect sights and sounds are gone in an instant, but odours linger. A scent trail is a snapshot of the past, because it tells a 12
dog not only that another animal passed by this spot, but how long it lingered before moving on, and what direction it went. Special glands called apocrine glands secrete the pheromones that carry information about an animal s age, sex, health, and even emotional state. In humans the apocrine glands are found in their highest concentrations in the armpits and groin area. Dogs (and most other mammals) have these glands spread over their entire body, even in hair follicles. This means that a dog s fur gets coated with pheromones and bacteria begins to act on these secretions almost immediately to modify and intensify the smell. Reading pheromone scents for a dog, is the equivalent of reading a message about the condition, status and feelings of another animal. Via pheromone scents dogs can pick up information on another animal s gender, age, health, and mood, as well as a lot of sexual information such as where a female is in the oestrous cycle, if she is pregnant and even if she has given birth recently. Many pheromone chemicals are found in dog s urine, so sniffing a telegraph pole or a tree along a route popular with other dogs, gives a great deal of information about the dog or dog s that have gone by previously. Dogs prefer to mark vertical surfaces with urine because having the scent above ground level allows the air to carry it farther. How high above the ground tells other dogs something about the size of the dog that made it. In dogs, physical size is an important factor in determining physical dominance, and since dominance seems to be more important to males, they have developed the habit of lifting the leg when they urinate in order to aim their urine higher. Urine marking also conveys information about a dog s emotional state. Whether a dog is stressed, excited, angry or fearful can be interpreted through the pheromones in its urine. It is not uncommon to witness a dog begin to growl and become agitated as a reaction to what it is finding out while sniffing where another dog has urinated. Some people claim that a dog can smell fear in a human. As you may have noticed, dogs spend a longer time sniffing at dogs they are unfamiliar with, however even dogs that live in the same household will sniff each other often. This is so they can get a quick update on whether their housemate is 13
well or unwell, and also so they can catch an advanced warning of any negative or aggressive feelings. Humans are sometimes embarrassed when a dog comes sniffing them in the crotch. A dog is attracted to the human groin area because it is a rich source of pheromone scents, and consequently, unfamiliar humans can be singled out for the most attention. People who have had sexual intercourse recently will often attract this type of attention from dogs. Women who are menstruating or who have given birth recently, will also find dogs may impolitely sniff at their groin area. Separating Odours; The concept that canines have the ability to pick out one scent from hundreds can boggle the mind. A dog can keep track of a single animal, even though its track has been crossed, recrossed, and trampled over by a whole heard of animals of the same species. Our own ability to recognize one scent is easily lost when that scent is covered with stronger odour of another kind. For example, we can enjoy the smell of a rose, however if that rose is smeared with faeces, we lose the scent of the rose as it is drowned out by the far more pungent smell. This doesn t happen to a dog. If dogs did not have the ability to separate one scent from another and to ignore the irrelevant odours while concentrating on the important ones, we would not be able to use them in the many jobs we require of them. For example, terrorists have been apprehended trying to smuggle explosives past dogs by hiding them in sacks of coffee. Another tried to hide explosives in a sealed plastic pale containing soiled baby nappies (diapers), and yet another buried dynamite two feet underground, only to have an explosive-detecting dog find it. Dogs are used to detect drugs and narcotics as well. In one celebrated case in Arkansas in the USA, a police officer working with a Labrador retriever was inspecting a vehicle when the dog alerted the officer that drugs were present. Officers searched the vehicle thoroughly but found nothing, yet the dog continued to indicate that drugs were present. The search continued but still nothing was found. The dog seemed preoccupied with the outside of the car along its side near the petrol cap, so the police decided to probe inside the tank itself. There, immersed in a tank of petrol was a sealed plastic container filled with 16 kg (35 lbs) of marijuana. 14
The Importance of Touch: In dogs, touch is associated with the arousal of emotions and the formation of emotional bonds. This begins when the dog is a pup. A puppy has special heat sensors in its nose which have either disappeared or ceased to function once the dog matures. These heat sensors are located around the nostril slits and when the puppy swings its head, these sensors pick up the heat source of its mother. Once the pup senses the heat source it will follow the heat trail back to her until she is touched. The touch of its mother creates a sense of security and wellbeing in the pup. It will immediately stop whimpering and curl up against her and drift off to sleep. It is clear that touch is very important to dogs from birth in the development of emotional bonds and, like humans, dogs have different places on their body that are more sensitive to touch than others. The nose, muzzle, and feet have a large supply of sensory nerves. The pads of the feet have specialized nerves that alert the dog to vibration and allow it to determine how stable the surface upon which it is stepping or running. The base of each hair follicle on a dog s body also contains nerves that send touch information to the brain. Dogs have a unique group of hairs that are embedded more deeply into the skin than other hair and have a higher concentration of touch receptors at their base than other hairs. These are the dog s whiskers or vibrissae. The nerve groups in each individual vibrissa can actually be traced to a specific location in the dog s brain. This strongly suggests that great importance is assigned to information from the dog s whiskers. There is evidence to suggest that a dog s vibrissae help it to detect changes in atmospheric conditions that may warn the animal of an approaching change to the weather. Vibrissae also inform the dog if something is approaching its face when it is asleep, thus helping the dog to protect its face and eyes. Also, because dog s eyes do not focus well on very close objects, the vibrissae also inform the dog of the texture and location of objects near its mouth. Emotional wellbeing: 15
One of the most important aspects of touch for a dog is in the role it plays in the dog s emotional well-being. Touch is critical for establishing emotional and social bonds among dogs and between dogs and people. Touch can have a calming effect for a dog whether it is provided by a human or another dog. If a dog is stressed or anxious because it is in a strange environment, or feeling isolated and alone, or exposed to an unpleasant event, being gently petted or being able to lie with a familiar dog, can have a marked soothing effect. Petting should occur with the dog maintaining body contact with the person doing the petting, like leaning against the person or sitting or lying down. And the best type of petting is more like a massage to the dog s shoulders back and neck muscles, than a simple pat on the head. The idea with petting is not just to ruffle the fur or move the skin, but to massage the underlying muscles as well. And in addition to stroking the dog with medium to firm pressure, the person should talk to the dog gently and soothingly. Hugging: One form of touch that most dogs, and certainly cats, hate is extended periods of hugging. Many pet owners make the mistake of anthropomorphizing (that s placing human likes, dislikes and thought processes onto an animal) their dog or cat by assuming that because people find hugging pleasurable, so do animals. Dogs and cats perceive hugging as confining and restricting their movement, and freedom of movement (for all animals), to run from a threat or defend themselves, is important for their wellbeing and survival. When you hug a dog or a cat you effectively immobilize it, which raises the animal s anxiety level. Many dogs and cats will put up with hugging from their owner for a short period, however they will soon struggle to free themselves. Dogs may become anxious enough to snap or threaten in order to break free and a cat will use its claws to try to climb out of the restricted environment. Puppies and touch: Puppies that are touched often early in their lives (even before being weaned) tend to display lasting positive effects such as increased vitality, higher activity levels, and greater disease resistance. Psychologically, these dogs exhibit more confidence, are more socially responsive, and are less likely to display negative emotional reactions. This is also true of cats. 16
Body Temperature: Canine normal body temperature range is 38-39.2 Celsius (100.5-102.5 Fahrenheit). A body temperature below or above these marks warrants an immediate call to a veterinarian. Body temperature in dogs is most often measured rectally. Ear thermometers can also be used, but it can be difficult to get an accurate reading. Gauging body temperature by the moistness of the nose or how warm the ears feel is not reliable. Some dogs will allow you to take their temperature, but others don t like it. It might be easier if you get another person to assist by holding the dog. Then do the following: 1. If using a mercury thermometer, remember to shake it with a quick flick of the wrist until the mercury is below 30 degrees C (94 F). Then lubricate the thermometer with petroleum jelly, KY jelly or other water-based lubricant. 2. Have your helper hold the head and front part of the body by tightly hugging the dog. 3. Lift the tail and insert the thermometer slowly and carefully into the rectum, located just below the base of the tail. Insert the thermometer about 3 cms (1 inch) and hold in place two minutes for mercury thermometers or until the digital thermometer beeps. 4. Remove the thermometer and read the temperature. Respiratory Rate: Respiratory rate is the number of breaths per minute. Normal respiratory rates are assessed when the dog is resting (18-34 breaths per minute). A dog that is in pain, having heart or respiratory problems, suffering from heatstroke, or simply excited will usually have increased respiratory rates, however it is important to gauge the overall situation and condition of the animal. If a dog has been at rest for more than 10 minutes, has plenty of fresh water available, yet seems to be excessively panting, see a vet as soon as possible. Personality: Do dogs have personalities? In order to respond to this question we must first establish what personality is, with respect to animals. For example, it is not appropriate to say that one dog 17
has a greater sense of humour than another, or is more formal, or optimistic, or judgemental. To do this would be to transfer human personality traits to dogs and that is a form of anthropomorphism. This does not mean that dogs are without personality however. Anyone who has been around dogs for any length of time will realise that some dogs are more extroverted than others; some are more vocal than others; some are more dominant than others, and so forth. Animal behaviourists today score personality characteristics in dog breeds by ranking them in comparison to other dog breeds. Instead of sorting dog breeds into sociable or not sociable for example, breeds are ranked against each other. So we might say that golden retrievers are more sociable than boxers, who are more sociable than Akitas. Some personality characteristics are inherent to the sex of the dog. Generally speaking male dogs display more aggression towards other dogs and more dominance over their owners. They are generally more playful, more active, and more territorial. Females tend to be more obedient and easier to housetrain. They are often more demanding of affection. Further information on Personality can be found in the Unit on Breeds. Genetics versus Learning: Swiss researchers from Berne University have shown that genes contribute significantly to the personality traits they tested in the areas of temperament, stability, self-confidence and resilience. Podberscek and Serpell in their studies on aggression in dogs in the 1980s found that it was a genetically determined characteristic. Does this mean that we can predict the personality of a dog when it is still a pup in the litter? To some extent, yes. Due to the genetic heritability of many personality traits, observing the personality of the sire and dam should give us a fair idea of the predisposition towards those traits that is contained in the pups. As for choosing among the litter, the sex of the pup will make a difference because males are more likely to possess a stable, less easily frightened nature, and have a higher drive to accomplish tasks. On the other hand, males also tend 18
to be more socially dominant, and have a higher defensive tendency (territorial) expressed aggressively. Even though personality tendencies have a large genetic component, a dog s adult personality is also shaped, to some degree, by its early experiences as well. Genes predispose a dog to certain personality characteristics that will manifest themselves behaviourally given a healthy and caring environment. But, though these genetic predispositions will bias a pup toward a particular personality, the pup s primary carer, as it grows up, will ultimately shape the dog s eventual personality by the experiences and socialization that is provided for it in the early part of its life. Following are examples of where a dog s genetic predisposition toward a certain personality trait is firstly, not permitted to develop and secondly, is actually suppressed, thus producing a different personality. # A dog has high sociability traits that give it a predisposition toward friendliness with people and other dogs. This dog finds itself owned by a person who isolates it from contact with anyone other than the owner. The genetic propensity toward socialisation does not teach a dog (or a person for that matter) how to appropriately express that personality trait. That has to be learned. So a dog who has been kept isolated from people and other dogs, may possess a personality that drives it to want to be sociable, but when it finally comes in contact with another person or dog, it doesn t know how to do it, and is soon recognised as socially inept. # A dog has high sociability traits that give it a predisposition toward friendliness with people and other dogs, but has been beaten by the only people or person it knows, or has been savaged by the only other dog or dogs it has come into contact with. This dog will learn not to trust people or other dogs. It will have a genetic propensity to want to draw near to people, for example, but will have learned that people are dangerous and so it will keep its distance, thus seeming unfriendly to people; the opposite of its personality trait. SOME COMMON MYTHS & MISCONCEPTIONS: Dogs should have a litter before they are spayed. This is not true. Dogs that have a litter before they are spayed are not better for it in any way. In fact, spayed dogs are at lower risk for breast cancer and uterine infections. 19
This myth may be responsible for the deaths of millions of dogs each year as unwanted animals are euthanized in overcrowded shelters. Beyond preventing unplanned pregnancies, spaying a female dog before her first heat cycle has been shown to cut down on certain types of cancer that develop later in life, such as mammary gland tumours. So, contrary to common belief, having a litter is not necessary for a female dog to feel fulfilled. Dogs operate on instinct, and if reproduction hormones are eliminated through spaying, the dog feels no urge to reproduce. Dogs are sick when their noses are warm. The temperature of a dogs nose does not indicate health or illness or if they have a fever. There is an old wives tale that cold wet noses indicate health, and warm or dry noses indicate illness. The only accurate method to assess a dog's temperature is to take it with a thermometer (see previous information - Body Temperature page 25). The state of a dog s snout is no sure sign of health. Veterinarians agree that a dog may still have a cold, wet nose while running a high temperature. Conversely, an afternoon romp in the middle of summer may leave a dog with a dry, warm nose. Mixed breeds (mutts) are healthier than purebred dogs. This is not true with regard to their ability or otherwise to fight off illnesses and diseases. Both mixed breeds and purebred dogs can be unhealthy. Where this idea may have arisen, is in the area of genetic predispositions to certain physical problems. For example, where Dachshunds as a breed, can be prone to spinal disc problems because of their elongated spine and short legs, a Dachshund cross (mixed breed) may have a shorter spine and longer legs and thus be less predisposed to spinal disc problems. All dogs like to be petted on their heads. Some dogs do like to be petted on their heads and some dogs don t. This is a bit like saying that all humans like to have their feet rubbed some do some don t. A wagging tail means a happy dog. Not necessarily. Aggressive dogs often wag their tails too. There are several physical body motions and cues that help dogs to communicate their intent. A wagging tail can mean agitation or excitement. A dog that wags its tail slowly and 20
swings its rear end, or crouches down in the classic play bow position, is displaying a friendly wag. Tails that are wagged when held higher, or while held over the back may be associated with aggression. There s no sure thing with the wag. You have to take account of the whole dog. It is how the tail is wagged that s important. Before approaching an unfamiliar dog, consider its entire demeanour. Signs of aggression can include any combination of snarling, laid-back ears, raised hackles, an assertive stance and a raised, slightly wagging tail. Because dogs communicate with their tails, take the time to learn what different uses of this appendage mean. Only male dogs will hump or lift their leg to urinate. Female dogs, especially dominant female dogs, will lift their leg to urinate and hump other dogs or objects. This can be true even if they are spayed. Table scraps are good for dogs. Wrong! Some table scraps such as bones and pieces of fat can be extremely dangerous to dogs. They may not digest the bones and this can create bowl blockage, which will require surgery to repair. Fat may cause gastrointestinal problems such as pancreatitis. Garlic prevents fleas. Many dog owners swear by the effectiveness of such natural flea-control methods and use them year after year; however, no scientific evidence supports these claims, and caution should be used because garlic eaten in quantity can in fact cause anaemia. Dogs eat grass when they are sick. Many scientists believe grass was once part of their normal diet and eating small amounts is normal. It is normal for dogs to eat grass in very small amounts, because it is roughage. We tend to see a problem with the consumption of grass when dogs don t have access to it all year long. When they re exposed to fresh grass, they tend to eat too much and can t digest it. Because large quantities act as an irritant, the dog throws up. The owner then thinks the dog ate the grass to induce vomiting because it is sick. 21
Dogs like tasty food. Dogs have very poor taste buds in comparison to humans. Many dog owners make the mistake of anthropomorphizing their pet dog when it comes to the taste of food. That s why many dogs have poor diets that result in illness, obesity and teeth problems. Dogs do not like the taste of food in the same way humans do. Don t make the mistake of assuming that because a dog gulped something down, that it liked the taste. To a dog, food pretty much any food is something to like and eat with gusto. Scraps off the table that are tasty to humans are a very poor substitute for a balanced dog diet. Licking is healing. It is natural for a dog to lick its wound but this is not necessarily always healing. In fact, too much licking can actually prohibit healing. A small amount of licking does help to clean a wound, but excessive licking tends to do more harm than good. A dog owner can help speed healing and prevent further damage by protecting a wound from the dog s abrasive tongue. Some veterinarians will fit a restrictive collar (Elizabethan collar) to a dog to prevent it from excessive licking of a wound. Dogs will let you know when they are sick. This is not necessarily true; in fact the opposite is more often the case. It is a survival instinct in dogs to be very good at hiding the fact that they are sick in order not to appear vulnerable. Often, by the time a dog openly displays that it is sick, the disease or condition is quite advanced. Indoor dogs don t need heartworm prevention. Indoor pets are also at risk for heartworm disease. Heartworm disease is spread by mosquitoes which can come inside. Dogs eat rocks, lick concrete or eat faeces because of nutrient imbalances. No one knows why dogs eat stuff they shouldn t eat, and so no simple explanation exists for this perplexing problem. If a veterinary examination reveals no medical problem, owners should consult an animal behaviourist. To give a dog a healthy, shiny coat, feed it raw eggs. 22
Studies have shown biotin (an important B-complex vitamin) deficiencies in humans and animals that consume large amounts of raw egg whites. So feeding dogs a high-quality canine diet is a much more healthful way of ensuring a shiny coat. Cooked eggs pose no danger and can be offered as an occasional treat for dogs not at risk for obesity. Certain breeds, such as Poodles, are hypoallergenic. Allergic people usually react to dander. As a dog grooms and licks itself, saliva is deposited on the skin and coat. As it dries, microscopic bits of the saliva, or dander, enter the air and environment and affect the owner. Poodles don t shed, and that may help to some degree, but it doesn t make them allergy free. Frequent shampooing of the dog can keep accumulation of dander to a minimum, as can regular washing of bedding and vacuuming of carpets. Many people also find a household HEPA air filter helpful. Simply keeping the dog out of the bedroom provides tremendous relief to some people. 23