Dog Sense (30 page)

The range of dogs' negative emotions is thus largely dominated by anxiety and fear, with anger appearing more sporadically. Individual dogs vary greatly in terms of both how intensely they feel each of these emotions and, to an even greater extent, what external events trigger them. All, especially fear, are powerful promoters of learning, and so if a situation provokes a particular emotion once, it is likely to do so again if repeated. Fear and anxiety are associated with obvious body-language, although the precise form in which this appears varies from dog to dog: Some dogs have learned that the best way to reduce their emotional discomfort is to move away from the source, while others may in the past have been given little choice other than to confront the problem directly. Thus aggression (aggressive behavior) may be associated with either fear or anger—or, indeed, with no emotion at all, as in predatory “aggression.”

The physiological basis for positive emotions is less well understood than fear, anxiety, and anger (mainly because in human medicine it's much more important to characterize and treat the latter, which are involved in many psychiatric disorders). Nevertheless, research suggests that the limbic system, including the amygdalae and the hypothalamus, is among the key structures and that the neurohormone dopamine is also crucially involved. One brain region that is especially important for positive emotions is the nucleus accumbens, the brain's “pleasure center,” which is situated quite close to the amygdalae.

Happiness
—joy—seems to radiate from the majority of dogs much of the time. Happy dogs have relaxed, open faces and bodies that wiggle from the shoulders backward—including the tail, of course. (But note that the tail may also be wagged when the dog is unsure and in conflict.) A cynic might say that dogs are conning us—that they merely behave as if they were happy, because happy-looking dogs are more likely to be well looked after than a grumpy dog. But scientists firmly believe that mammals such as dogs do experience happiness.

There are good evolutionary arguments for the existence of happiness as a modulator and stimulator of beneficial behavior. At its most basic level, learning theory postulates that all behavior needs to be rewarded if it is to be repeated. Hunger causes an animal to seek out food; and once it is found and eaten, hormones released from the gut reinforce the behavior, making it more likely that the dog will seek out and eat that food again. However, if there is something wrong with the food, and it makes the dog sick, then other hormone systems trigger an aversion. The dog will be unlikely to eat that particular food again for a long time—and may even avoid the place where it found the food.
⁹

These straightforward examples posit the presence of an immediate reward or punishment to trigger learning. However, other equally important types of behavior are not associated with any obvious reward and therefore must be performed simply because they make the animal feel good—in other words, happy. In the autumn, squirrels bury nuts in the ground rather than eat them so that they will have food for the winter. It is unlikely that a squirrel in its first year of life has the foresight to know that (a) bad weather is coming, (b) there won't be much food available then, and (c) if it buries food that is abundant now, the food will still be nutritious in a few months' time. More likely, evolution has shaped the squirrel's behavior such that burying food and memorizing its location has become rewarding in itself. In other words, this activity makes the squirrel happy.

Likewise, biologists used to have trouble understanding what motivates play behavior. In wild animals, play must promote survival; otherwise evolution would select against it—a young animal playing out in the open is much more obvious to a predator than one sleeping in its den. However, the benefits of play usually don't become apparent until months
later, when they emerge in the form of better social integration or more sophisticated hunting techniques. Again, the simplest explanation is that play is self-rewarding. In other words, it's fun! And not just fun to watch—play actually generates happiness in the participants. Indeed, play and happiness seem inextricably linked in dogs, consistent with the idea that they are wolves that never grew up. It can take very little to bring about happiness in a well-cared-for dog; for example, when a dog catches sight of a favorite toy and starts playing with it spontaneously, that impromptu activity will have been generated by the feeling of happiness that the dog recalls from the last time it played with that toy. Dogs are also presumably happy when they're with their owners, but the overriding emotion in this case will be love.

Love
—that which biologists, nervous about being misunderstood, call “attachment”—fuels the bond between dog and master or mistress. For a young wolf, a strong attachment to its parents is crucial to survival. The parents have all the skills necessary to protect and nurture the young cub—and while it is growing up the cub can pick up those skills for itself, simply by observing and imitating its parents, rather than having to learn each one by trial and error. If it leaves the family group too early, the chances of surviving long enough to become a parent are significantly reduced. It's difficult to see how such a strong and essential attachment could not be emotionally based, given the underlying physiological machinery. If we accept the probability that dogs derive much of their typical behavior from the repertoire of the juvenile wolf, then it's logical that their emotions should be similarly derived. In short, there's a sound
biological
reason for supposing that dogs
actually
love us rather than just appearing to do so.

At the physiological level, love is distinct from other positive emotions in that it specifically involves the hormone oxytocin. Originally this hormone was believed to be a trigger solely for care of newborns by their mothers (i.e., nurturant behavior), but it is now thought to be involved in all kinds of attachment. In fact, dogs experience a surge of oxytocin during friendly interactions with people. It's widely believed that interaction with dogs is a good stress-buster for humans. The reverse is probably also true. In one study, researchers set up a series of
friendly interactions between dogs and people, consisting of stroking and gentle play.
¹⁰
In the course of playing, the dogs' blood pressure dropped slightly, as expected, and the circulating levels of several hormones increased dramatically. (Specifically, oxytocin quintupled and endorphins as well as dopamine doubled.) Similar, though less dramatic, changes occurred in the people.

The remarkable thing about this strong physiological response is that it is triggered by contact with
Homo sapiens
, a different species. As noted earlier, dogs' attachment to people is often
more
intense than attachment to individuals of their own species; dogs that become very upset when their owners go out are rarely comforted by the presence of other dogs. It's tempting to speculate that “one-man dogs” may lack oxytocin, but so far no one has looked into this possibility. What scientists do know, however, is that all dogs have been programmed by domestication to have intense emotional reactions toward people. This lies at the root of the “unconditional love” that many owners describe and treasure in their dogs. Such intense feelings are not easily turned off, as attested by the high proportion of dogs that hate being left alone (as many as one in five, according to one of my surveys).

Dogs really
do
miss their owners when they are separated from them. Many dogs also seem to become much more emotionally fragile under these circumstances; for example, they react much more negatively to sudden shocks, such as the noise of fireworks going off. In this sense, the capacity for love that makes dogs such rewarding companions has a flipside: They find it difficult to cope without us. Since we humans have programmed this vulnerability, it's our responsibility to ensure that our dogs do not suffer as a result.

Without love, the dog-owner bond would not function. Yet, as we have seen, it is such a powerful emotion in dogs that many become anxious whenever they guess that they are about to be parted from their owner and then remain anxious until they are reunited. This frequently leads to behavior that the owner finds unacceptable. In the past, such problematic behavior was often dismissed as “wickedness” on the dog's part, but we now know that it is actually deeply seated in the emotions of love and anxiety.

Separation distress

Dogs often leave all too visible signs that they hate being left alone, although these can be misinterpreted by owners who don't appreciate just how attached to them their dogs really are. The veterinary profession usually refers to cases of dogs that misbehave when alone as separation
anxiety
, but since it's not clear that all such cases are primarily due to the emotional state of anxiety (some are due to the dog panicking when it's been startled by some external event), I prefer to use the term “separation distress” when describing the symptoms.

Separation distress can take a variety of forms, depending on the dog's breed and personality. Manifestations include destructiveness (biting, chewing, and scratching of furniture or other materials, often close to the place where its owner has most recently left the premises and, in some cases, involving items bearing the owner's scent); vocalization (barking, whining, or howling); and elimination (urinating, defecating, or vomiting). Rarer symptoms include such signs of chronic and unbearable stress as self-mutilation and repetitive pacing.

I started researching separation problems more than a decade and a half ago
¹¹
in response to an ill-conceived study purporting to show that dogs that had been through rescue and rehoming were very likely to develop separation distress. This conclusion placed the responsibility for separation problems firmly at the door of the rehoming charities. The study even suggested that every dog being rehomed should be given a course of anxiolytics (anti-anxiety drugs) to tide it over during its first few weeks in its new home. There was very little research to support this assertion at the time, apart from an investigation showing that mongrels were more likely than dogs with pedigrees to have separation problems. Animal charities rehome far more mongrels than purebreds, so therefore it must be their fault! In fact, my subsequent research has detected that rehomed dogs do have a slightly increased risk of developing separation distress, but this finding can probably be accounted for by the large number of dogs that are relinquished by their owners because they can't be left alone.

Indeed, pedigree dogs are far from immune to separation distress, as my first longitudinal study showed.
¹²
My colleagues and I followed the development of seven litters of Labrador retrievers and five litters of border collies—forty puppies in all—from the time they were eight weeks old (and still with their breeders) to eighteen months of age. I was expecting that a few of these dogs might dislike being left alone. To our amazement, well over 50 percent of the Labs and almost half of the collies showed some kind of separation distress lasting for more than a month, peaking at about one year of age.

Our survey opened our eyes to the real scope of the problem. Based on 676 interviews with dog owners, we found that 17 percent of their dogs were currently showing signs of separation-induced distress and
that a further 18 percent had done so in the past but had recovered, mostly without the owners seeking any specialist help. But many other dogs suffer from separation distress that is unrecognized by their owners. In another study, we recruited twenty dog owners who were certain that their dogs were happy to be left in the house while they went to work.
¹³
We then filmed each dog when it was left alone. Three dogs showed signs of separation distress (pacing, panting, or whining) that their owners were completely unaware of. One case was so severe that we recommended an immediate clinical consultation. Since separation distress is, by definition, something that happens when no one's there, with hindsight it's not surprising that only its more obvious manifestations—chewing, elimination, barking, or howling that's loud enough for the neighbors to object to—tend to come to the attention of owners. While the sample taken in this study was tiny, it does suggest that research based on the self-reporting of owners considerably underestimates the real scope of the problem.

If we assume that approximately 20 percent of dogs suffer from separation distress, then the implications across the entire dog population are truly staggering. Of an estimated 8 million dogs in the UK, my figures indicate that at any one time
more than 1.5 million
are suffering in this way.
¹⁴
And of the 70-plus million dogs in the United States, it's likely that
well over 10 million
may be experiencing separation distress.
¹⁵
This is happening now, today. Such numbers suggest a real ongoing crisis for dogs—and a totally preventable one. Separation distress could be virtually eliminated if every young dog, before it is left alone for any length of time, were trained to expect that departures lead to reunions (see the box titled “
Home Alone: Can Dogs Be Trained to Cope?
”). Once established, it is much more difficult to cure.