News: Guest Posts
Toy Alert
Study finds Hormone-disrupting Chemicals Leach from Some Plastic Toys

The toy aisle is meant to be all about fun, but recalls, toxic imports and a dearth of regulations have left dog owners facing tough choices. Many toys are made of plastic and may contain chemicals that interfere with hormones.

A new study by researchers at the Institute of Environmental and Human Health at Texas Tech University shows that BPA and phthalates, chemicals that disrupt hormones, “readily leach” from plastic or vinyl bumper toys used to train retrievers.

Philip Smith, a toxicologist and co-author of the as-yet unpublished study, uses plastic bumpers to train his Labrador Retrievers, Bindi, age 11, and Huck, age 5. He wondered if the bumpers might expose them to hazardous chemicals.

In fact, the compounds are hard to avoid. BPA, the building block of polycarbonate plastic, is found in most food and drink cans; phthalates are common in food packaging, personal care items and vinyl plastics.

“BPA and phthalates come from many, many sources” besides pet toys, Smith says. So a dog’s “cumulative exposure may be significant.”

The study, conducted by graduate student, Kim Wooten, is one of the first to examine these chemicals in pet toys. In children’s toys, some phthalates have been banned in the U.S. and the European Union. In July 2012, the U.S. Food and Drug Administration banned BPA in baby bottles and children’s drinking cups.

Although their health effects in dogs are unknown, the hormones they interfere with regulate many biological functions.

Studies done mostly with rodents have linked BPA and phthalates to impaired development of reproductive organs, decreased fertility, diabetes and obesity, cancers, and behavioral and attention problems.

No, dogs are not mice. There are “species sensitivity differences” in regard to toxics, Smith says. For example, dogs are at greater risk than humans from eating chocolate. But while their sensitivity to synthetic chemicals may also differ, “we are unaware of specific reasons why they might respond in a significantly different manner.”

Available data suggests that the most vulnerable pets may be pregnant females “and perhaps young animals like puppies.”

According to a 2012 pet health report by Banfield Pet Hospital, some cancers and other diseases in dogs are increasing. “The rate of overweight and obese pets has reached epidemic levels in the U.S., affecting approximately one in five dogs and cats.”

The causes are unknown, but Smith says it’s possible that endocrine-disrupting chemicals, including phthalates and BPA, play a role.

Certain aspects of canine cancer suggest that dogs are sensitive to them, he says. For instance, exposure to estrogens raises the risk for mammary cancers. For metabolic disorders such as obesity and diabetes, researchers are finding that some hormone-disrupting chemicals appear to “affect metabolic endpoints, in addition to reproduction and behavior.”

For the toy study, the researchers tested orange and white bumpers from two unidentified makers, using artificial saliva to simulate a dog chewing a bumper. The amount of toxics released in a dog’s mouth couldn’t be determined due to the use of simulated saliva,

But what is a high exposure in dogs?

“We are not aware of any exposure guidelines pertaining to these particular chemicals and dogs,” Smith says.

They suspect the levels released from the bumpers would be very high, though, compared with children’s toys.

The study also examined BPA and phthalates from ordinary plastic pet toys sold in stores. The bumpers leached more, but the results suggest that the other toys might have released other hormonally-active chemicals.

Smith highlights the uncertainty that shoppers face, saying the bumpers might have been made from different materials, or perhaps the packaging limited the release of some chemicals before the experiment.

Or, the less affected toys may have involved “materials that are also used in the manufacture of children’s toys.”

“We’re not really sure, but intend to pursue the question further.”

Good thing for pet owners.

“Given the extent of plastics in the human-canine environment,” Smith says, avoiding the chemicals entirely may not be possible.

But not all plastics are the same. When it comes to leaching of chemicals “each type is very different.”

“That is why studies on individual products are important.” Pet owners need the information “to make thoughtful decisions.”

Some pet toy makers say they use BPA-free plastics.

But owners may wonder why it’s even a question. Why should they have to worry about chemicals in toys or migrating from cans, even into “organic” food, to add to their dog’s exposure?

At least—at last—it is being studied.

Smith’s team plans to continue studying the exposure of pets to chemicals. “We think there is a great deal to be learned about potential pet and human health impacts from chemicals in the environment,” he says.

And as they learn, Smith says they hope to yield the data needed “to inform decisions about how we manufacture pet products, which ones we buy, and what we allow our pets to chew.”

Good Dog: Studies & Research
Do DNA Tests Reveal Genetic Secrets?
The Beauty of Diversity

For those of us who love dogs, using DNA tests to deconstruct our mongrel pooch’s mysterious heritage is appealing because we want to be able to answer the question, “What kind of dog is that?” Companies say that DNA-based diagnostic tests, which sell for about $60, can answer the question by comparing your dog’s DNA to over 100 of the most popular breeds. But are the tests accurate? I decided to find out.

Chance, a 10-year-old mixed-breed dog who has lived with me for six years, was my guinea pig. I tested his DNA using three different tests. In 2008, when I wrote the prequel to this article (read it online at thebark.com/dna), I had his ancestry tested with the Canine Heritage Breed Test. At that time, the company used 96 markers and tracked them to 38 breeds. A marker is a gene or DNA sequence on a chromosome that indicates “breedness.” The labs claim that the markers they use are 99 percent accurate.

In May 2012, when I began doing research for this follow-up article, I tested his DNA with the amplified Canine Heritage Breed Test again because it had been substantially improved to 400 markers and 120 popular breeds. I could have paid $25 to upgrade the 2008 test. But to be fair in my test-of-the-tests experiment, I submitted his cheek swab under a different name and without a photograph, just in case, as many people believe, the tests are a scam. In addition, I used the MARS Wisdom Panel Mixed Breed Identification Test. Mars looks at 321 markers and includes 185 breeds in its database.*

To analyze and compare the results fairly, I needed to find out if the tests were processed the same way, and I researched the history of the breeds identified in Chance’s ancestry.

Comparing the Tests
Each lab analyzes DNA the same way. Upon arrival, samples are logged, tracked and monitored. DNA is extracted from the cheek swab and isolated, and copies are made to ensure a sufficient amount for processing. The genetic material is then chemically enhanced and run through equipment that looks for markers in the dog’s DNA that match breed markers in the database.

If a primary parent breed can’t be identified in the DNA, the program will look for a secondary grandparent breed, and so on and so forth, until it eventually clusters with a distant breed (if there is one). If there are no purebred ancestors, remnant breeds will be sought.

To identify markers that characterize a breed, labs take samples from multiple thousands of individual dogs representative of more than a hundred breeds. However, those dogs differ from one laboratory to the next. Although their sample sizes are big enough to absorb minor differences, no two dogs are exactly alike. Plus, line-bred dogs can affect results. For example, Labrador Retrievers bred exclusively for hunting may be more like each other than they are like the breed.

Finally, descriptive terminology differs. Canine Heritage uses primary, secondary and in the mix. Wisdom Panel uses parent, grandparent, great-grandparent and next best breed matches that include percentiles.

Chance’s Results
In total, I tested Chance’s DNA three times. I used the Canine Heritage test twice, in 2008 and 2012, to find out if the expanded breed library would affect the results. (It did.) I also used Mars Veterinary’s Wisdom Panel**. Although results differed, cumulatively the tests indicate that Chance is a mix derived primarily from spitz dogs and large terriers, with a tablespoon of sight hound, teaspoon of herding dog, pinch of guard dog and smidgen of bird dog.

Because Chance has no purebred parent, his strongest signal would come from a purebred grandparent. One test indicated a Siberian Husky grandparent. However, the other two tests claimed he has no purebred parent, grandparent or great grandparent. In any case, all three tests concur that a combination of spitz breeds provides the strongest signals in Chance’s ancestry — Siberian Husky, Alaskan Malamute and, to a lesser degree, the Pembroke Welsh Corgi, a breed with some spitz lineage. Although it transmits a faint signal, the Pembroke Welsh Corgi is the only breed that showed up in more than one test. The white German Shepherd and blackand-tan German Shepherd, strong and weak signals respectively, are both named as ancestors and are admixtures of one another. Although they are herding dogs, it’s probable that both breeds have some spitz lineage. The Japanese Chin, a miniature Asian breed derived thousands of years ago from larger mastiff and spitz dogs, is also a fairly strong signal.

Large terriers make up the next strongest signals in his DNA. The German Pinscher, Standard Schnauzer and Doberman Pinscher are closely related. German Pinschers were used to develop the relatively new Doberman Pinscher breed. The Standard Schnauzer, originally called the Wire-haired Pinscher, is directly related to the German Pinscher. Sight hounds are mentioned in two tests. In the late 1800s, Borzois were likely mixed with Huskies to increase speed, and terriers were mixed with Italian Greyhounds.

The weakest signals, in some cases less than 2 percent of his makeup, include a ragtag group of breeds, including Border Collie, English Setter, Cocker Spaniel and Leonberger.

Making Sense of the Findings
Cumulatively, the three tests indicate that Chance is related to 16 different breeds within all AKC breed groups except scent hounds. So the question shouldn’t be, “What kind of dog is that?” A more appropriate query is, “What kind of dog isn’t that?”

The ancestral breeds named in the three tests seem absurdly disparate, but they are not contradictory. They all point to one truth: only a few degrees of separation differentiate Chance from all modern breeds. This is because most purebred dogs have a crippling lack of genetic diversity, which is the unintended consequence of modern breeding practices.

Except for 14 ancient breeds — Afghan, Akita, American Eskimo, Basenji, Canaan Dog, Chinese Shar-Pei, Chow Chow, Dingo, Finnish Spitz, New Guinea Singing Dog, Saluki, Samoyed, Shiba Inu, and Siberian Husky — all our modern breeds were developed in the last few hundred years.1 Although each has its own DNA fingerprint, they have so little genetic diversity that if you go back far enough, the DNA of almost every dog, mixed breed or purebred, will cluster with a few common ancestors. This finding raises the question, “How can breeds that look so different be so closely related.”

The complex DNA of stray mutts on the mean streets of, for instance, Lugazi, Uganda, or Zorzor, Liberia, may answer the question. Ubiquitous freeranging dogs living on the fringes of human settlement are not, as previously believed, semi-feral, mongrelized purebred dogs, but rather, are genetically distinct and subject to the pressures of natural selection. Some populations have been isolated for hundreds, if not thousands, of years. Subsequently the village dog genome remains complex and unabridged.

Suspecting that village dogs may be pure genetic remnants of ancient dogs, Adam Boyko, assistant professor in the Biomedical Sciences Department at the Cornell University College of Veterinary Medicine, co-founded the Village Dog Genetic Diversity Project with his colleague Carlos Bustamante, a genetics professor at Stanford School of Medicine.

The project is a worldwide collaboration of researchers, volunteers and veterinarians who gather canine DNA samples along with photos and information on weight, age, body measurements and coat color. The samples are analyzed at the Canine DNA Bank at the Baker Institute for Animal Health, part of Cornell’s College of Veterinary Medicine, which maintains a growing DNA archive of dogs worldwide.

The scientists believe their work will shed new light on when, where and under what conditions dogs were domesticated, and how dogs have adapted to human settlement, environmental stress and disease.

The first phase of the study included collecting samples from modern breeds, their mixed-breed relatives, breeds reputed to be from remote regions of the world and African village dogs. In 2009, they reported that African village dogs are a mosaic of indigenous dogs descended from more ancient dogs that migrated to Africa.2 Findings also indicated that their genome is being eroded at an alarmingly fast rate as they mate with recently introduced modern dogs. Researchers are now scrambling to find dogs in even more remote locations. In the summer of 2012, workers began collecting DNA samples in Liberia and the Democratic Republic of the Congo.

On a continuum, gray wolves, the progenitor of all dogs, have the most genetic diversity, and purebred dogs have the least. Village dogs’ diversity lies somewhere in between. Because purebred dogs are the result of strong selection for exaggerated traits, they have only a fraction of the genetic diversity displayed by village dogs. The genetic variant that underlies a desirable trait, whether it’s extreme size or intense behavior, has become fixed, wiping away not only competing variants but also variants associated with nearby genes.

Genes located close to each other on a chromosome are said to be linked, and tend to be inherited together or, conversely, wiped away at the same time. Thus, a trait that isn’t selected for can be wiped away simply as a result of being in the wrong place at the wrong time. If that trait happens to affect, for instance, immune response to disease, then that could be a problem.

By comparing the genome of village dogs to that of purebred dogs, scientists hope to be able to identify what’s been lost as a result of intense artificial selection. Dr. Boyko notes that “village dogs offer a chance to understand the mechanisms of certain genetic diseases. Knowing what those genetic variants are might be the first step towards invigorating genetic diversity in some modern breeds.”

The Significance of Canine Origin
The closer a village dog population is to the original canine domestication event, the closer it will be to the gray wolf and the more genetic diversity it will have. Will Dr. Boyko’s village dogs turn out to be close relatives of the first dogs? Not likely.

Previous studies suggest that dogs originated in places as varied as Eastern Europe, China’s Yangtze River Valley and the Middle East. In a 2002 study, researchers pinpointed East Asia as the place of origin. However, some scientists think these dogs are descendents of an even older population that developed in a different place. Dr. Boyko’s findings confirm this. African village dogs have about the same amount of genetic diversity as those in the East Asian study, suggesting that both groups are the same age. It’s possible that both populations originated together somewhere else and then migrated to East Asia and Africa at about the same time.

To thoroughly complicate matters, the Canidae family does not play by the same rules as most other mammalian families. Unlike, say, horses and donkeys, dogs, wolves, coyotes and golden jackals can interbreed and produce fertile offspring. Consequently, following the genetic trail from domestic dog to wolf leads to a lot of stops and starts and many dead ends as well as plenty of headaches for evolutionary biologists.

A Multi-Disciplinary Approach
Where to now? Some researchers think it’s time to go back to the road not taken. In a paper published in June 2012, Greger Larson, an evolutionary biologist in Durham University’s Department of Archaeology and the paper’s lead author, said that by putting genetic discoveries in the context of archaeology, history and biogeography, the study of the geographical distribution of species might help make better sense of what we already know.3

As Dr. Larson notes, “There has been so much admixture since dog domestication began, and especially in the last few hundred years, that looking at modern dogs is always going to be problematic. There may be modern populations that are less ‘corrupted’ or admixed, but even they will possess a legacy of several thousand years of crosses with large numbers of populations, and even wolves.” He adds, “The only way forward is to focus on other methods, including, but not limited to, ancient DNA from archaeological dog and wolf remains. And of course, there is the wider interpretation and understanding from lots of other fi elds to put it all in context.”

In the paper, researchers discussed an interesting pattern that emerges when sites with archaeological dog and wolf remains are overlaid onto maps showing the historical distribution of wolves. First, the archaeological remains are not found in the places where ancient breeds are believed to have been developed, intimating that dogs may have been domesticated multiple times from local wolf populations. Second, most of the ancient breeds come from areas where wolves never ranged, suggesting that humans had dogs as they migrated around the globe. Furthermore, dogs only appeared in these locations after agriculture was introduced.

The canine genome’s full story continues to evade scientists, but as DNA technology advances and analysis becomes cheaper and faster, researchers are optimistic that the answers they seek are right around the corner.

Will I continue to test my future shelter rescue mutts to find out who they are, even though I know that the answers will be the same — all modern dogs are so closely related that it’s almost impossible to discriminate ancestry? Probably. Other mysteries lie hidden in our dogs’ DNA. The idea that an animal can be morphed into so many extreme shapes and behaviors yet remain a simple combination of only a few stem parents is one of them.

We like to believe that scientific discovery advances tidily, fact by fact, to prove an irrefutable truth. But science is a messy business. And there is hardly a better example of just how messy than the search to tease out the mysteries hidden in the canine genome.

Good Dog: Behavior & Training
The American Gut Project
Seeking samples from you and your pets

The gut microbiome is a factor in a range of diseases such as cancer, inflammatory bowel disease and cancer, all of which are more common in Westernized populations of both pets and people. A new study called the American Gut Project is seeking to investigate how diet affects the gastrointestinal microbiome.

Previous work studying microbiomes of typical healthy adult humans raised questions about how their results apply to the entire population and to other species. Scientists with this project hope to collect samples from individuals with a full range of diets and lifestyles.

So far, research projects on this subject in dogs and cats include just a few small studies of lab animals or those that were ill. The fact that the American Gut Project will address the microbiomes in the intestinal tracts of large numbers of dogs (and cats) living in a variety of settings means that the results could yield useful information about the effects of diet, genetics, and lifestyle on the gut microbiomes of our pets. Such information may help us make informed decisions about how to feed and care for our dogs (and cats) in the future.

It is a goal of the project to collect samples from multiple individuals in the same household. If you want to participate in the study, along with your family members of the canine and feline variety, or if you want to learn more about the American Gut Project, click here.

Good Dog: Studies & Research
Why Dogs Fear Thunderstorms
Q&A with Nancy Dreschel, DVM

Nancy Dreschel has long been interested in the ways people and animals interact. She got her degree in veterinary medicine from Cornell University, but her lifelong interest in behavior led her to return to graduate school five years ago to pursue a PhD in biobehavioral health at Penn State University. She, her husband and their two sons share their home with one dog, two cats, four fish and a mouse.

In her recent study, "Physiological and behavioral reactivity to stress in thunderstorm-phobic dogs and their caregivers,"* Dr. Dreschel investigated stress responses—pacing, salivating, panting, trembling, whining, hiding, increased salivary cortisol levels—of dogs with thunderstorm phobia and their human caregivers when both were exposed to simulated thunderstorms. Listening to a simulated storm elicited behavioral and physiological responses in nearly all the dogs, but not in their human caregivers. The way the dogs responded was not influenced by their caregivers’ reactions, or by how close the relationship was between person and dog. But dogs who lived with other dogs had less change in salivary cortisol levels and a more complete return to baseline levels by 40 minutes after the simulated thunderstorm than did dogs in single-dog households. Dogs in multidog households had slightly higher baseline levels of salivary cortisol. (For more, see “Is a Dog a Dog’s Best Friend?,” Jan/Feb 06.) The Bark recently interviewed Dr. Dreschel about her work.

Bark: How did you get interested in this subject?

Nancy Dreschel: My colleague Dr. Doug Granger, and the Behavioral Endocrinology Laboratory at Penn State are well known for their research on salivary hormone measurement, particularly in children. I was struck by the ease of saliva collection and thought that it would be a nice, noninvasive way to measure stress in dogs as well as in people. Thunderstorm phobia seems to be particularly frustrating for people and particularly stressful for dogs. I feel strongly about the humane use of animals and am interested in developing tools to measure stress in welfare situations.

B: How do you define stress?

ND: In order to define stress, I think you first have to understand that all aspects of living systems are [intended to be] in balance. Things constantly affect our physiological and psychological states, and our bodies respond to keep everything in homeostasis, or equilibrium. I define stress as being anything that knocks this off, including immune stressors (being exposed to a virulent disease), environmental stressors (being wet and standing outside on a 20-degrees-below-zero day) or mental stressors (enduring a thunderstorm if you are terrified of them).

B: Could baseline cortisol levels be affected by the difficulty that some people had in collecting the samples—wouldn’t the “phobic” dog demonstrate stress simply as a result of the collection process itself?

ND: Specimens collected on the control day did not show any increase in cortisol, which is what would be expected if the collection method itself caused stress. [On the control day, there was no simulated thunderstorm.] It should be noted that these dogs were behaviorally quite normal, other than their very specific fear of storms.

B: Are you familiar with any other studies that have measured the cortisol levels in multidog households?

ND: No—this was the first (and only) study I know of to measure cortisol in a home situation. Salivary cortisol has been measured in shelters and research facilities, however.

B: What sorts of clinical applications do you imagine could result from your research on dogs with thunderstorm phobia?

ND: Collecting saliva from dogs is a minimally invasive procedure that can be done by regular people in a number of different settings. I could see this procedure being used in studies of dogs with anxiety, in stressful situations and in welfare applications. I also think it could possibly be used to determine if dogs on medication for anxiety or fear are responding physiologically as well as behaviorally.

B: What kind of treatment program do you advise for people whose dogs have thunderstorm phobia?

ND: I recommend a number of individualized programs for dogs with thunderstorm phobia, including offering a “safe” place to go (covered crate, basement, etc.), behavior modification (counter-conditioning and desensitization), pheromone therapy and anti-anxiety medication. Many dogs require medication in order to calm down enough to be able to learn new behaviors.

B: What do you think is the most significant result of the study?

ND: I think the most significant result is finding the degree of increase in cortisol that these dogs experienced and the fact that it lasted so long. When I think of the number of dogs who experience similar stressors (which might range from a car ride to panic when left alone), I wonder if all these experiences are accompanied by a similar physiological reaction. We know by their behavior that some dogs become upset by certain situations, but these results show that a physiological response that could have adverse health effects is also occurring.

B: Why do you think the presence of other dogs in the household had an effect on cortisol reactivity in dogs with thunderstorm phobia? Is the higher baseline a key factor in the faster return to near-baseline levels?

ND: I’m not sure why living with other dogs had an effect in our subjects. Their baseline cortisol levels were somewhat higher to begin with, which could indicate they were under more stress on a regular basis. I think it is likely that something about living with other dogs mediates how their stress-response works. Maybe the day-to-day interactions better prepare the hypothalamic/pituitary/adrenal axis for response to major stressors.

I would emphasize that the dogs that lived with other dogs didn’t “seem” calmer—behaviorally, there was no difference. Because this was a fairly small study, it is hard to draw many conclusions about the multiple-dog findings.

B: Did the other dogs actually do anything to alleviate stress in these dogs?

ND: What struck me was a total lack of “comforting” as we define it in human terms, from the other dogs in the household. We think of comforting as having a shoulder to cry on, a hug, a gentle word or listening ear. Many of the dogs in our study (both those who lived with other dogs and those who were the only dog) sought out this type of comforting from their human companions. However, there was very little, if any, physical contact between the dogs in this study. Many of the non-subject dogs in the household weren’t even present during the procedure—the caregivers had isolated them in other rooms so they only had to deal with the subject dog.

B: Our magazine promotes adoption of shelter/rescue dogs, and likes to think that dogs benefit by living in multidog households (with compatible canines, of course). Is there any scientific basis for this?

ND: I think our research provides some evidence to support this statement. However, I do not recommend that people with storm-phobic dogs run out and obtain another dog, thinking that will make their dog’s problem go away. The dogs who lived in multidog households still had thunderstorm phobia and severe behavioral responses, despite the fact that they lived with other dogs.

*Published with co-author Douglas Granger, PhD, in Applied Animal Behaviour Science 95: 153–168.


Good Dog: Studies & Research
Do Animals Have Emotions?
Of course they do

One of the hottest questions in the study of animal behavior is, “Do animals have emotions?” And the simple and correct answer is, “Of course they do.” Just look at them, listen to them and, if you dare, smell the odors that pour out when they interact with friends and foes. Look at their faces, tails, bodies and, most importantly, their eyes. What we see on the outside tells us a lot about what’s happening inside animals’ heads and hearts. Animal emotions aren’t all that mysterious.

When I first began my studies three decades ago—asking the question, “What does it feel like to be a dog or a wolf?”—researchers were almost all skeptics who spent their time wondering if dogs, cats, chimpanzees and other animals felt anything. Since feelings don’t fit under a microscope, these scientists usually didn’t find any, and, as I like to say, I’m glad I wasn’t their dog!

But now there are far fewer skeptics; prestigious scientific journals publish essays on joy in rats, grief in elephants and empathy in mice and no one blinks. The question of real importance is not whether animals have emotions, but why animal emotions have evolved. Simply put, emotions have evolved as adaptations in numerous species. They serve as a social glue to bond animals with one another and also catalyze and regulate a wide variety of social encounters among friends and foes.

Emotions permit animals to behave adaptively and flexibly, using various behavior patterns in a wide variety of venues. Research has shown that mice are empathic rodents, but it turns out they’re fun-loving as well. We also read accounts of pleasure-seeking iguanas; amorous whales; angry baboons; elephants who suffer from psychological flashbacks and post-traumatic stress disorder (PTSD—elephants have a huge hippocampus, a brain structure in the limbic system that’s important in processing emotions); grieving otters, magpies and donkeys; sentient fish; and a sighted dog who serves as a “seeing-eye dog” for his blind canine buddy. Today, the paradigm has shifted to such an extent that the burden of “proof” now falls on those who still argue that animals don’t experience emotions.

Many researchers also recognize that we must be anthropomorphic (attribute human traits to animals) when we discuss animal emotions, but that if we do it carefully, we can still give due consideration to the animals’ points of view. No matter what we call it, researchers agree that animals and humans share many traits, including emotions. Thus, we’re not inserting something human into animals; rather, we’re identifying commonalities and then using human language to communicate what we observe. Being anthropomorphic is doing what’s natural and necessary to understand animal emotions.

We might expect to find close, enduring and endearing emotional relationships between members of the same species, but improbable relationships also occur between animals of wildly different species, even between animals who are normally predator and prey! Such is the case for Aochan, a rat snake, who befriended a dwarf hamster named Gohan at Tokyo’s Mutsugoro Okoku Zoo, and a lioness in northern Kenya who adopted a baby oryx (usually an appetizer before a larger meal) on five different occasions.

It’s bad biology to argue against the existence of animal emotions. Scientific research in evolutionary biology, cognitive ethology (the study of animal minds) and social neuroscience support the view that numerous and diverse animals have rich and deep emotional lives. (Here I focus on mammals, although there are data showing that birds and perhaps fish experience various emotions as well as pain and suffering.)

Charles Darwin’s well-accepted ideas about evolutionary continuity—that differences among species are differences in degree rather than kind—argue strongly for the presence of animal emotions, empathy and moral behavior. Continuity allows us to connect the “evolutionary dots” among different species to highlight similarities in evolved traits, including individual feelings and passions. All mammals (including humans) share neuroanatomical structures, such as the amygdala and neurochemical pathways in the limbic system that are important for feelings.

Mirror neurons help explain feelings such as empathy. Research on these neurons supports the notion that individuals can feel the feelings of others. Mirror neurons allow us to understand another individual’s behavior by imagining ourselves performing the same behavior and then mentally projecting ourselves into the other individual’s shoes.

To what degree various species share this capability remains to be seen, but there is compelling evidence that humans are not alone in possessing it. Diana monkeys and chimpanzees help one another acquire food, and elephants comfort others in distress. Mirror neurons also help explain observations of rhesus monkeys who won’t accept food if another monkey suffers when they do so, and empathic mice who react more strongly to painful stimuli after they observed other mice in pain.

The borders between “them” and “us” are murky and permeable, and the study of animal emotions helps inform the big question of just who we are. Another big question for which answers are revealed by studying animal passions is, “Can animals be moral beings?” In my development of the phenomenon that I call “wild justice,” I argue that they can. Many animals know right from wrong and live according to a moral code.

When people tell me that they love animals because they’re feeling beings and then go on to abuse them, I tell them that I’m glad they don’t love me. I often ask researchers who conduct invasive work with animals or people who work on factory farms, “Would you do that to your dog?” Some are startled to hear this question, but if people won’t do something to their own dog that they do daily to other dogs or to mice, rats, cats, monkeys, pigs, cows, elephants or chimpanzees, we need to know why. There’s no doubt whatsoever that, when it comes to what we can and cannot do to other animals, it’s their emotions that should inform our discussions and our actions on their behalf.

Emotions are the gifts of our ancestors. We have them, and so do other animals. We must never forget this. When it comes to animal welfare, we can always do better. Most of the time, “good welfare” is not good enough.


Good Dog: Studies & Research
The "D" Word: Dominance
We talk about dominance, but do we really understand it?

If a dog has behavior issues such as a tendency to mount other dogs, any form of aggression, an overly pushy play style or poor response to training, some people are sure to claim that “dominance” is the culprit. But are they right?

The ongoing dialogue about dominance in the dog world is more problematic than an unattended puppy in a shoe store but it’s unlikely to go away anytime soon. While some hate the concept so much that they refer to it as the “D-word,” others swear by it, considering it an indispensable guiding principle for all interactions with dogs. Having a civil discussion on the subject, much less reaching a consensus, is a challenge, as debates often become quite heated.

Scientific inquiry offers an opportunity for greater understanding of this topic, though writings on the subject with titles such as “Social dominance: Useful construct or quagmire?,” “Social dominance is not a myth: Wolves, dogs, and other animals” and “Deconstructing the concept of dominance: Should we revive the concept of dominance in dogs?” reflect continued controversy. While dominance, or social dominance as it is often called, has been studied extensively in a number of species, relatively little work has been done in this area on the domestic dog, and more research is badly needed.

Defining Dominance
To further complicate an already contentious debate, “dominance” has multiple meanings. As James O’Heare notes, “Often, researchers argue over social dominance without agreeing on a clear definition, and perhaps have different definitions in mind.” There are a variety of ways to characterize it. In his study “The concept and definition of dominance in animal behaviour,” Carlos Drews reviewed 13 different definitions of dominance and pointed out that criticisms of one are not necessarily applicable to others.

Adding to the frustration and confusion, when it comes to domestic dogs the term is commonly applied to two different types of relationships. The first relates to interactions between dogs. In this usage, dominance is defined as the power to control access to desirable resources and refers to the relative status of two dogs. In the absence of another dog, an individual dog cannot be said to be “dominant” as a personality attribute because dominance refers to the relationship between dogs.

The second, and more controversial, type of dominance relationship relates to interactions between humans and dogs. In this paradigm, humans dominating dogs is considered the path to well-trained dogs. Those who follow this school of thought claim that you have to control your dogs by being dominant over them in order to make them behave and may make suggestions such as not allowing your dog to sleep on your bed or walk through the door ahead of you, or even to spitting in your dog’s food and making a resting dog move rather than walking around him. Today, fewer trainers subscribe to these ideas than in the past.

Dominance Between Dogs
The few scholarly investigations of dominance relationships between dogs have found the concept relevant to their interactions with one another, and scientists who study social relationships aren’t surprised. For example, Marc Bekoff, PhD — ethologist and professor emeritus at the University of Colorado who has had a major influence on the scientific understanding of dogs as well as many other species — observed that “in the real world, dogs are social beings, and social beings form dominance relationships, just as their wild relatives do.”

Becky Trisko, PhD, ethologist and owner of Unleashed in Evanston, Ill., focused her 2011 doctoral dissertation on social interactions within a group of 24 dogs who regularly engaged with one another at daycare. The behaviors she analyzed included aggressive threat and conflict, muzzle lick, crouch, passive submission, retreat, high posture, muzzle bite, mount and chin-over.

Trisko found a dominance hierarchy among the dogs, although only about 30 percent of the pairs had clear dominance relationships. Dominance rank correlated with age (older dogs tended to rank more highly) but not with size. And contrary to popular belief, neither mounting nor performing chinovers were related to status. As a point of interest, not once in 224 hours of observation during this yearlong study did she observe an “alpha roll.”

Muzzle licking was consistently done by subordinate dogs to individuals of higher rank and was highly predictive of relationships between individuals. The clearest signals were those associated with voluntary submission, or deference. Trisko observed that dominance relationships were not about coercion, force or fighting, but rather, about an understanding by both individuals of their relative social status.

In another study exploring dominance relationships between dogs, Simona Cafazzo and three colleagues observed a group of feral dogs in the suburbs of Rome. Their primary finding was that the dogs formed a linear dominance hierarchy, meaning that the individuals in the group could be ranked in order from highest to lowest in status. (Other possible social structures include having one individual who dominates all others who are equally low-ranking or societies in which the relationships are not transitive— e.g. A dominates B, B dominates C, C dominates A). A linear dominance hierarchy indicates that the dogs in this study were capable of forming stable social groups, although many have claimed that feral dogs cannot do so. Additionally, they found that submissive behavior was most predictive of dominance relationships, rank correlated with age, and males within an age class outranked females. Rank order in the linear dominance hierarchy predicted access to food resources, with those of higher rank having priority access.

Dominance has been studied in puppies as well as in adult dogs. John Bradshaw and Helen Nott reported that interactions between littermates were inconsistent over time, and that observations of such interactions did not predict which puppy would come out on top in any competitive situation; “winners” varied from one day to the next. Despite much discussion of choosing (or avoiding) the dominant puppy in a litter, interactions between littermates do not reveal dominance relationships, much less any kind of linear hierarchy.

The Dangers of Misunderstanding Dominance
Conversations about dominance relationships between dogs are often tense, but discussions of the concept within the context of relationships between humans and dogs are sometimes nothing short of explosive. Many of the strongest objections stem from using it to endorse force-based, coercive styles of training. According to Trisko, “Dominance has been wrongly equated with aggression and used to rationalize the use of physical force and intimidation by humans toward dogs. Misunderstandings of the concept of dominance have led to unnecessary physical punishments and abuse of dogs by humans.”

While no studies have thoroughly investigated whether dominance relationships exist between people and dogs, there is evidence that such training styles can create problems. Herron et al. investigated such techniques, often called “dominance reduction training,” and found them to be counterproductive. The confrontational methods associated with training styles that insist that we “get dominance over our dogs” caused aggressive responses in 25 percent of the dogs in their study. Techniques such as grabbing a dog by the jowls and shaking; hitting or kicking; staring; performing alpha rolls (also called “dominance downs”) and physically forcing a dog to release an item were more likely to result in aggressive behavior than were gentler, positive methods. Using such forceful methods can actually create problem behavior as well as increase a dog’s fear and anxiety. Based on what we know about dominance relationships between dogs, this is not surprising. As Trisko notes, “If dominance relationships between dogs and humans are at all similar to dominance relationships between dogs, then dominance does not apply to all relationships and when it does apply, it does not require the use of intimidation or physical force.”

A basic ethological premise is that we must understand the animals we study. In fact, this principle is considered so absolute that it is most often phrased as a commandment: Know thy animal! Understanding how social dominance does and does not apply to dogs is part of knowing who dogs are. Trisko makes this point: “If we really want to understand our dogs’ behavior, especially their relationships with other dogs, ignoring dominance will hinder us.” Bekoff agrees. “That’s who they are, that’s how they behave. They form status relationships, and we have to understand that.”

When it comes to the issue of dominance, common ground is not easy to find. Few would dispute the need for further research, though even the most carefully designed studies may not be enough to bring agreement on this particular subject. As Bekoff has noted, “People get on this kick with dominance. They don’t pay attention to the data.”

Arguments about dominance and its relevance to dogs, their relationships with each other, and our relationships with them are sure to continue. Though I prefer resolution to conflict, I can’t help but see the wisdom in moralist and essayist Joseph Joubert’s remark: “It is better to debate a question without settling it than to settle a question without debating it."

Good Dog: Studies & Research
Education: Gone to the Dogs
Canines claim their territory on college campuses

Summer has faded into fall and it’s time for dog lovers — and dogs too — to head to college, where dogs are taking their place in the dorm, the psych lab and even the classroom.

While some dogs simply kick back and enjoy campus life at a university with pet-friendly housing, such as Eckerd College in St. Petersburg, Fla., or Stephens College in Columbia, Mo., others give their intellectual muscles a workout by participating in research studies designed to test their ability to think and solve problems.

Dogs are taking their place in collegelevel human studies as well. At several universities, they dominate the syllabi of courses devoted to companion-animal behavior and welfare. Other schools offer entire classes or majors focused on the human-canine connection.

To a dog lover, the appeal of taking a dog to college is obvious, as is the draw of canine-focused study — but what’s in it for the dogs? While it has long been possible to study animal science, wildlife management or food-animal husbandry, formal study of dogs in academia is a relatively new phenomenon. As recently as the 1990s, academic researchers who wanted to focus on Canis lupus familiaris were greeted with raised eyebrows, ridicule or worse. But the nascent fields of anthrozoology — the study of human-animal relationships — and cynology — the study of the domestic dog — are growing quickly in academia.

Applying academic rigor to the study of dogs can increase our understanding of their abilities and deepen our bond with them, ultimately resulting in improving their treatment by society as a whole. These goals spurred the development of the country’s first anthrozoology program and the establishment of a university wholly devoted to the study of dogs. Both of these pioneering efforts are part of a growing collection of canine-focused educational options.

When Anne Perkins was head of the psychology department at Carroll College in Helena, Mont., she was dissatisfied with existing animal-focused study options, which were basically limited to animal science and zoology. “These programs were not addressing why we love our animals so much,” she says. Perkins spent a 2005 sabbatical designing a new program, anthrozoology, which would “study the value of animals from an academic, scholarly perspective.” The new program was first offered as a minor at Carroll in 2007.

“I bit it off in pieces,” she says, adding one class at a time. The students wanted more; the minor grew into a major, and Carroll offered the nation’s first bachelor of arts in anthrozoology in 2011. The bachelor’s degree “embedded the study [of the animal-human bond] in traditional fields,” where research is peer-reviewed and published in scholarly journals, Perkins says.

Carroll College anthrozoology students focus on either horses or dogs. Students in the canine track examine theories of domestication and attachment. They study puppy development, socialization and learning, and they practice assessing temperament. Seniors raise puppies, preparing them for a broad range of doggie careers, including scent work, assistance and acting.

Like Perkins, Bonita Bergin, founder and president of Bergin University of Canine Studies (BUCS), argues that academic study is essential to improving the status and treatment of dogs. As BUCS graduates leave the Rohnert Park, Calif., campus to teach or run businesses that model ethical humancanine relationships, “we hope to enrich the understanding of the relationship that has inspired and fulfilled so many,” Bergin says. “We also hope to help eradicate the horror of euthanasia of unwanted dogs.” Offering post-secondary study wasn’t enough for Bergin; she also wanted the respect of academic peers. Tenacious as a terrier, Bergin spent three years pursuing her vision: the world’s first accredited university focusing on our canine pals and partners. Why? “I believed the dog deserved it,” she says simply.

Undergraduate and graduate students at BUCS explore the influence of genetics and heredity on dogs’ behavior and temperament. They also analyze the growing body of published research on dogs, and are encouraged to contribute original research of their own. But it’s not all books and theory. Puppies and service-dogs-in-training fill the campus with hands-on opportunities. The associate degree program, in particular, emphasizes dog training and socialization; starting the day students help out with the whelping process.

Bergin has revolutionized earlypuppy education. BUCS students begin “formally” training puppies as soon as the puppies open their eyes at about four weeks of age. The astonishing result is that most puppies respond eagerly and accurately to more than a dozen verbal cues by the time they are eight weeks old.

On the opposite side of the country, dog-loving students at SUNY Cobleskill choose among a half-dozen dog-focused electives in the animal science department. “[The courses] are designed to give students a solid understanding of the important factors involved in producing good working dogs and the behavioral basis of popular training techniques, emphasizing positive, reward-based approaches,” says Stephen Mackenzie, professor of animal science at the university. According to Mackenzie, a canine management major is in the works. Dogloving students “can work dogs almost every semester they are here,” he adds, training dogs for anything from offleash obedience and agility to tracking, trailing, air scenting and detector work “under the guidance of someone with good academic credentials.”

At some universities, dog scholars have to search for dog-related material buried like treasured bones among more traditional offerings. The psychology department at the University of Michigan, for example, offers “Dog Cognition, Behavior and Welfare,” a popular course taught by Camille Ward. The class, described as “for people who love dogs and want to learn about them from many different avenues,” has a long waiting list. Also in the psychology department, Dr. Barbara Smuts teaches “Behavior of Wolves & Dogs”; she also offers students the opportunity to participate in research projects on dogs’ social behavior.

At Barnard College, in New York City, Dr. Alexandra Horowitz (author of Inside of a Dog) teaches a psychology class on canine cognition. At Eckerd College, a course on animal learning and training includes considerable material on dogs, says its instructor, Lauren Highfill. The Center for the Human-Animal Bond at Purdue University in West Lafayette, Ind., offers companion-animal welfare and management courses that primarily focus on dogs and cats. Graduate students can head to Tufts University for a master’s program in animals in public policy that includes study of companion animals, or to Harvard, where psychology grad students can take a seminar called “Puzzles of the Mind: Humans, Animals, Robots.”

At Canisius College in Buffalo, N.Y., dogs figure prominently in undergraduate coursework on the social organization of animals, animal learning and applied animal behavior. And the college’s master of anthrozoology coursework includes a popular class on companion animals in society. A dog-human relationships expert was recently hired, and Canisius plans to expand its dog-centered offerings, says Michael Noonan, professor of animal behavior, ecology and conservation.

We’ve come far since 17th-century philosopher René Descartes asserted that animals lacked the ability to feel pain, yet cruel treatment of dogs is still far too common. Canisius prepares animal-behavior graduates to eradicate that cruelty and to “make the world a better place in the way we interact with animals” by providing a “strong, science- based education balanced with critical thinking and ethics,” Noonan says. “From the science, we see that they [animals] are more like us than was thought in the past.” Therefore, “most ethics that apply to us apply to them — animals are sentient beings whose concerns matter.”

Some schools recognize the importance of the human-animal bond by allowing pets in selected on-campus housing units — about a dozen colleges nationwide have at least one pet-friendly dorm. Other schools conduct research studies that aim to improve understanding of dogs’ abilities and view of the world. Indeed, new evidence of dogs’ intelligence, creativity and ability to understand and communicate their concerns is uncovered daily at cognition labs, where dogs take center stage.

New York City dogs can join cognition studies in Horowitz’s lab at Barnard where anthropomorphic beliefs about dogs are tested with an emphasis on “getting the dog’s perspective,” rather than a more traditional behavior-focused approach, said researcher and Bark contributing editor Julie Hecht. Current studies examine dogs’ understanding of the concept of “fairness” and the way they use their noses in daily life. “We’re trying to better understand the dog’s perspective, but we are, of course, limited by our human perspective,” and sometimes the hardest part is separating the two, she said.

Southern dogs have a choice of schools: Duke University (Durham, N.C.), the University of Florida (Gainesville), the University of Kentucky and Eckerd College all recruit local canine “students” for their research. Current studies examine whether dogs can count, how dogs form trusting relationships with humans, dogs’ interpretation of human social gestures, and canine imitation and social learning.

The studies might sound esoteric, but they can lead to real changes in the way people regard and teach dogs: Watching four-week-old puppies learn to sit, lie down and solve problems banishes forever any idea that training must involve force. Discovering that dogs can use pictures to indicate their preferences compels scientists to reexamine human-centered ideas that tie thinking to spoken language. And seeing how dogs’ behavior changes when they know that human “observers” are distracted hints at their ability to strategize.

The more we learn about dogs’ abilities, the greater the potential for true partnerships based on mutual respect rather than compulsion, says Bergin. “This is crucial in transitioning the dog from a backyard animal we see as disposable to recognizing the key role dogs play in the evolution and continued development of humans.”

Good Dog: Behavior & Training
Big dogs, Small dogs
Does size affect behavior?
Big vs Small Dogs

He chose the dog, but I chose the name,” the woman explained. Their dog was an especially petite Boston Terrier, but his name — Titan — was one more typically bestowed on a larger dog. I’d seen this type of incongruity before, and though it’s sometimes just for the sake of being ironic, often it’s about conflict. Couples who disagree about whether to add a large dog or a small dog to their family compromise by choosing a dog of one size and a name that’s usually given to a dog of another size. I’ve also met Pixie the Newfoundland, Tank the Bichon Frise, Bitsy the Bouvier and Goliath the Pug.

People often have strong opinions about what size dog best suits them. Some prefer small dogs because they’re more likely to be welcome everywhere, especially when traveling, while others gravitate to large dogs because they associate them with fun and friendliness, as well as kids and families. Sizebased biases are also common, and sad to say, I’ve heard a number of derogatory terms for both small and large dogs. And anyone with big dogs knows that people sometimes fear them even when their behavior is exemplary and a small dog is present whose behavior is not. One Bark reader implored me, “Don’t forget to cover that big dog stigma!”

Many people have asked the question, “How is the experience of having a large dog different than that of having a small dog?” Part of the answer may come from evaluating whether big and small dogs really are different in ways that extend beyond size, particularly in their behavior. Another piece of the puzzle involves determining if people’s behavior toward and expectations of dogs varies based on the dog’s size.

A Sizeable Spectrum
One of the marvels of domestic dogs is the astounding range of sizes they come in, which is determined by a very small number of genes. (In comparison, roughly 200 gene regions affect height in humans.) A dog’s size has practical consequences — just ask anyone with a Great Dane suffering from diarrhea, an experience that’s not the quite same for a person with a similarly afflicted Maltese. Likewise, dealing with a seven-pound Affenpinscher who prefers not to get into the car may require nothing more than matterof- factly picking her up and putting her inside. The situation is far more challenging when a 185-pound Saint Bernard’s involved. Big dogs can be more expensive in every way, from the cost of food, professional grooming and medication to toys, leashes, collars and food bowls.

People with little dogs who don’t want them to help themselves to food simply avoid picnicking on the floor and are careful not to leave chairs where they can be used as stepping stones to the table or counter. People with large dogs often find that no place lower than the top of the refrigerator is safe or truly off-limits. With a large dog, the accidental consumption of dangerous foods, such as chocolate, is far less likely to lead to serious consequences than for a smaller dog because it takes much more for the dose to be toxic to a larger dog. Similarly, the few extra treats that lead to weight gain in smaller dogs may be no big deal for a large dog. Finally, helping a large dog with mobility issues can be physically demanding for the caregiver.

Some worry about big dogs around children, but I must confess that I worry when we dog-sit a friend’s sixpound Pomeranian. My kids are gentle with him and do a good job of being kind and respectful, but I’m still worried that they’ll collide with him and cause an injury completely by accident, no matter how actively I’m supervising. With bigger dogs, that isn’t as much of a concern.

Many people point out the advantages of small dogs in urban environments: it’s easier to rent an apartment (weight limits favor them); tight living spaces may be easier to share; and getting small dogs into and out of an apartment building, especially while you’re housetraining them, is far less of a challenge. Yet traits that can be troublesome for urban living — high exercise needs, sound sensitivity, a tendency to bark excessively — have nothing to do with size. Some dogs are beautifully suited to life in the city, and others are not.

So, are behavioral differences sizebased? For the most part, the answer is a resounding “No!” Dogs of all sizes love to play chase, fetch, go on walks, run off leash, meet new people, romp with their best dog buddies, participate in training sessions and eat tasty treats. By the same token, dogs of all sizes are vulnerable to sound sensitivity, exhibit separation anxiety and aggression, jump on people inappropriately, bark to excess, chew on shoes, dig in the garden, or have accidents on the floor. They all wag their tails (if they have them!) in joy.

And yet, there are clearly differences between individual dogs, based perhaps on age, gender or the environment in which the dog lives and was raised. While the similarities in dogs of different sizes are far greater than the differences, can we deny those differences?
Should we?

Science Steps In
A 2010 research study (Arhant, et al.) examined the connection between size and behavior in great detail, addressing these questions: How does guardian behavior toward dogs of unequal sizes influence their dogs’ behavior? How do expectations of dogs based on their size differ? Do people treat large and small dogs differently? In the study, “small” and “large” were defined by weight; dogs less than 20 kg (44 pounds) were categorized as small and those equal to or more than that, as large.

The study’s most important overall finding? There are significant differences in behavior between large and small dogs and between guardians of large and small dogs. The researchers reported that a range of interactions between people and their dogs are related to the size of the dog.

Small dogs were reported to be less obedient, slightly more often aggressive or excitable, and more anxious and fearful. People with small dogs also reported a lower level of consistency in their interactions and enforcement of rules than did those with larger pups.

Much has been made of the practice of treating small dogs like babies, though it’s hardly surprising that it occurs. Babyish features affect human caretaking behavior; we’re evolutionarily hardwired to find big eyes, small size and proportionally large heads endearing. Psychologists call this the “Aww phenomenon.” If babies weren’t so cute, parents could be less likely to respond to their needs, and the offspring would be less likely to survive.

Dogs seem to elicit this same “aww” response in humans, especially small dogs, and even more so, breeds with pronounced juvenile features such as Cavalier King Charles Spaniels, Chihuahuas, Japanese Chins, Pugs and Boston Terriers. Since babies affect our hormones, raising the levels of oxytocin — nicknamed “the love hormone”— it stands to reason that adorable dogs do, too.

Socialization, Training and Other Interactions
Socialization is a key factor when it comes to dog behavior. Typically, large dogs have more opportunities for socialization than small ones. When small dogs are carried around rather than moving around on their own four paws, they have fewer interactions with people and other dogs, which can limit their ability to cope with them. Also, small dogs are often picked up or otherwise physically manipulated, which may result in more negative experiences with humans.

Many say that their small dogs are “people” dogs and don’t like other dogs; lots of people with big dogs say the same thing. Size notwithstanding, positive experiences with other dogs during puppyhood are the best way for a dog to develop good manners. Absent enough of those experiences, dogs of all sizes face social challenges.

Well-trained dogs are always a joy, but training is another way in which interactions between people and dogs differ based on size. Two research studies found that small dogs do not receive as much formal training as large dogs (Kobelt, et al.; Masters and McGreevy). Also, people play fetch more often and do more tugging and nose work with big dogs than with small ones, and are more likely to take them running or biking (Arhant, et al.). Arhant’s study concludes that differences in people’s behavior may account for the higher rates of disobedience in small dogs.

Codes of Conduct
It’s hard to make the case that a dog’s size has no bearing on what we consider acceptable, or what we allow them to do. Though many guardians have the same rules for dogs of any size, the code of conduct for large and small dogs is often different.

For example, small dogs are more likely to be allowed in our beds and on our laps (Westgarth, et al.). Practical considerations are at work here. Having a 25-pound dog jump or sit on you is one thing, but having a 100-pound dog do it is another. Others encourage little dogs to jump up on people and get on the furniture, but rarely invite big dogs to do so. Jumping up isn’t the only thing that’s treated differently. The behavior that is considered a nuisance in a small dog may be deemed antisocial in a large dog. Even aggression and other serious behavioral issues are more likely to be tolerated in small dogs.

As evidence that some people with small dogs don’t take undesirable behavior seriously, consider this story: an eight-pound Chihuahua escaped from his home, bit someone and was declared a dangerous dog. When a representative from animal control came, the dog’s people apparently thought it was a joke. One of them was reported to have said, “I broke out laughing. I said, ‘Look at the dog, do you see the dog going after you?’ The guy kind of got upset when I started laughing at him.”

For years, I have specialized in cases involving aggressive dogs, and to be honest, the size of the dog sometimes makes a difference in how I feel about the threat they represent. I once had a very aggressive Dachshund in my office, followed by a Chesapeake Bay Retriever with similar issues. During both appointments, I employed all the cautions necessary in this line of work. Still, throughout the appointment with the Chessie, I was aware of being afraid, while with the Doxie — though I knew I was at risk of being bitten if I made a mistake — I just didn’t feel the same anxiety. Both dogs were equally aggressive, but the size factor affected my fear response.

I’m not alone in reacting differently to aggressive dogs based on their size. Large dogs are more likely to be euthanized for aggression (Reisner, et al.), though another study (Guy, et al.) found that the average “biter” tended to be a smaller dog. It’s possible that greater tolerance for this behavior in small dogs allows genetic tendencies toward it to persist.

In some ways, there are correlations between size and breed characteristics. Many small dogs are terriers and earthdogs, types that have been deliberately developed to be tenacious and curious as well as to dig and explore. If dogs are bred for those characteristics, such behavior will have far more to do with genetic inf luences on behavior than with size.

Also related to breeding, Arhant, et al. found that small dogs were more likely than large dogs to come from pet stores, which generally acquire their “stock” from puppy mills. When you consider that puppy mills are notorious for environmental deprivation and risky breeding practices, it is perhaps no surprise that small dogs are burdened with more problematic behavior..

. . . . . . . . . . . . . .

What dogs do — their behavior! — is what makes them good company, great friends and essential members of our family, and very little of that has anything to do with size. When dog people swap stories, they are not about the size of the dog, but about the experiences we have in common — the joy, the angst, the training, the vet emergencies, the photos, the occasional chewed shoe, the games, the walks, the friendship, the fun and the love. It’s always a big love, no matter what size the dog.

Good Dog: Behavior & Training
Wet Dog Shake
The science behind the behavior

I had always assumed that dogs shake vigorously after a bath or a swim in order to share massive quantities of water with all people in the immediate vicinity. That hypothesis fits in with my philosophical view that dogs have a generosity of spirit that knows no bounds and that they love us very much. It also matches my personal experience as a dog groomer and as a dog guardian.

A recent study takes a far more scientific approach to this behavior. Mammals that are wet suffer the risk of hypothermia, so water removal is a serious issue. Animals who remain wet can use 20 percent of their daily energy staying warm and generating the heat necessary for evaporation of that water. If an animal can quickly and efficiently remove excess water, they will dry faster, suffering less risk from the cold and saving energy.

In “Wet mammals shake at tuned frequencies to dry”, Andrew Dickerson, Zachary Mills, and David Hu enlighten us about the specifics of shaking. They studied the water removal affects of shaking behavior in animals ranging in size from mice to bears, and including dogs.

These researchers observed mammals shaking themselves when wet and came to several conclusions. One is that there is a mathematical relationship between the size of the animal and the frequency with which they shake. The smaller an animal is, the more water they take on relative to body weight, and the faster they shake to remove that water. Smaller animals shake faster (at a rate of 29 oscillations per second for mice) while larger animals shake more slowly (4 oscillations per second for bears.) As animals in the middle of the size range studied, dogs had an intermediate rate of 5-7 oscillations per second depending on the size of the dog. The dogs in the study included members of various breeds: poodle, Labrador retriever, chow, Siberian Husky and Chihuahua.

Another conclusion of the researchers is that the ability of mammals to remove water relates to a property of their skin—its looseness. The amplitude of the shake is increased by loose skin. Though the rotation of the spinal column only reaches 30 degrees, the skin movement allows a total rotation of up to 90 degrees. Loose skin in mammals has previously been hypothesized to help with limb movement but this study suggests another function—extra movement in shaking that allows additional water removal.

If you’ve ever been near a wet dog shaking, it will come as no surprise at that dogs, as well as other mammals, can remove about 70 percent of the water from their fur with just a few seconds of shaking. The effectiveness of shaking behavior is extraordinary, though I must confess that I rarely appreciate it when I experience it at close range.

Dog's Life: Lifestyle
Dogs and Attachment Theory
A deep emotional connection with our pets brings many benefits

When I’m having a bad day, my dogs know just how to lighten the mood and bring a smile to my face. Pet lovers have long known that animals lower our stress levels, and that fact has been proven by scientific research over the years.

A new study published in the Journal of Research in Personality looks at the relationship we have with our pets from the perspective of attachment theory. Like parents or friends help people develop a sense of internal security and confidence, researchers believe that our pets help give us the confidence and support needed to live healthy lives.

Their study set out to prove the impact our animals have through two experiments.

Both studies had participants complete a “pet attachment questionnaire” that measured emotional connection. In the first experiment, they were asked to list their personal goals for the future and rate how likely they were to achieve them. In the second experiment, they had to perform an extremely difficult word test.

Some of the participants were asked to write a brief description of their pet before they completed the respective task. In the first study, researchers found that those who wrote about their pet generated more goals and expressed more confidence that they would achieve them as compared to the control group. In the second experiment, those who wrote about their pet had lower stress levels during the test than those who did not.

Interestingly this result was only found among those who had a high emotional connection to their pet. There was no benefit for people who had a distant relationship with their pups.

Non-dog lovers may never quite understand the special relationship we have with our pets, but I know that I owe my dogs so much thanks for the support and love they give me!