Dog's Life: Lifestyle
Dogs can diagnose lung cancer in humans
Earlier this week, I wrote about the depressing number of dogs affected by cancer. Many organizations and researchers are working towards finding a cure. Meanwhile, dogs may play an important part in curing humans.
Lung cancer is the the deadliest form of cancer worldwide, but current detection methods have been unreliable. Scientists are looking at a possible test for volatile organic compounds (VOCs), which have been linked to the presence of cancer, but it's been difficult to apply and no lung cancer-specific VOCs have been identified.
Researchers at Schillerhoehe Hospital in Germany decided to see if dogs could be used to identify the elusive lung cancer VOCs.
The study worked with 220 volunteers, including lung cancer patients, chronic obstructive pulmonary disease (COPD) patients, and healthy people. The dogs successfully identified 71 samples with lung cancer out of a possible 100. They also correctly detected 372 samples that did not have lung cancer out of a possible 400.
The researchers concluded that the dogs could detect lung cancer independently from COPD and tobacco smoke. The findings are a big step towards the accurate diagnosis of lung cancer.
I'm always amazed that despite all the technology in the world, sometimes the most powerful tool of all is a dog's nose!
Culture: Stories & Lit
Scientists have only recently caught on that canines are not just a fertile subject for their particular specialties — psychology, anthropology, zoology, ethology and more — but also a topic that the publishing world seems eager to promote.
This trend has been a long time developing. Nobel Prize–winner and ethology’s co-founder, Konrad Lorenz, wrote Man Meets Dog (1950), breaking ground that lay dormant until anthropologist Elizabeth Marshall Thomas’s bestseller, The Hidden Life of Dogs (1993), reintroduced the genre of dog studies to the non-scientist reader. A few years later, journalist Mark Derr followed up with Dog’s Best Friend (1997), a book that grew out of his Atlantic Monthly investigative piece about the AKC and the dog-show world. Another dry spell was finally broken by psychology professor Alexandra Horowitz’s Inside of a Dog (2009), which garnered an extraordinary amount of well-earned praise. At long last, it seems that the (overly) popular dog-memoir craze has given way to illuminating and well-researched books that explore the science behind our favorite species, written for the general public.
For example, in the May issue of Bark, we reviewed Dog Sense, a fascinating book by British anthrozoologist John Bradshaw, in which the author provides a compendium of current research (both his own and others’) into dogs’ origins and behavior. More specifically, he details their evolution from a wolf-like ancestor into proto-dogs and then the first domesticated species; he also investigates how this very long-term relationship has affected both canines and humans. He goes on to clearly explain how today’s dogs differ behaviorally and culturally from wolves, and why the dominance/ pack paradigm put forth by many trainers (including Cesar Millan) is not only the wrong way to understand dogs but has also done them a great disservice. It makes for engrossing and thought-provoking reading.
Paleoanthropologist Pat Shipman takes a similar synoptic approach in her engaging new book, The Animal Connection: A New Perspective on What Makes Us Human, and adds valuable insights into the dog’s evolutionary story. She combs through research in her own field as well as in archeology to test her hypothesis that animals (dogs among them) have shaped our species’ evolution. As she says, “I believe that a defining trait of the human species has been a connection with animals…. Defining traits are what make humans human … and they are partially or wholly encoded in our genes.” She does a rigorous investigation — every bit as compelling as a forensic TV drama — into the three big advances that contributed to our modernity: tool-making, language and symbolic behavior, and the domestication of other species to support this position.
In the chapter, “The Wolf at the Door,” Shipman suggests how domestication might have happened. As importantly, she refutes other theorists, such as Raymond Coppinger and his “protodog- as-village-pests” model. She writes about Belgian researcher Mietje Germonpré, whose work recently dated a proto-dog fossil skull to 31,680 BP — proving that dogs were domesticated long before humans congregated in settlements. (It was an amazing 20,000 years before the next species, the goat, was domesticated.) Shipman questions why so few representations of wolves/dogs (as well as human figures) appear in prehistoric art, and incorporates anthropologist Anne Pike-Tay’s suggestion that if domesticated dogs were helping us hunt, they were “perhaps placed in a completely different symbolic category from other animals,” adding, “dogs might have been put into the human family category as an extension of the hunter.” All of which attests to the fact that dogs have been a part of the human family since our own prehistory — an extremely long time.
All of these books, the classics and the current crop, should be read by dog lovers. Not only do they contribute to our understanding of our first friends, they also have the potential to improve dogs’ welfare by educating us as to what we can and can’t expect from them. We owe it to dogs to learn more so this age-old relationship can grow even stronger. Here’s hoping this trend continues and more groundbreaking books are on the way.
Avery Publishing, 320 pp., 2010; $26.00
After the birth of Snuppy, the world’s first cloned dog, a handful of biotech entrepreneurs envisioned a thriving business that would provide grieving dog lovers with genetically identical clones of their deceased pets. In Dog Inc., Pulitzer Prize-winning investigative journalist John Woestendiek exposes the grave folly behind those science-fiction dreams.
Woestendiek travels between the United States and South Korea, following the companies looking to cash in on cloning technology, and their clients, who hope cloning really will approximate resurrection.
Although much of the book focuses on the salacious story of Bernann McKinney, a woman obsessed with cloning her Pit Bull, the strength of Dog Inc. is in Woestendiek’s ability to lay out the science and laboratory politics in a way that’s both accessible and engaging. Readers will understand the X-inactivation process that made the first cloned cat so physically distinct from her progenitor — and, consequently, such a public relations failure — as well as the allegations of scientific fraud levied against Woo Suk Hwang, one of the pioneers of canine cloning.
Woestendiek never outright condemns canine cloning, but the details leave little question as to where he falls in the debate. He shines light on the poor treatment of the laboratory dogs used in cloning, the cloned puppies who do not survive the process and the heartbreaking fate of Snuppy himself. As for the actual clones, Dog Inc. tracks kittens, puppies and even a bull cloned at great financial and biological cost, only to prove physically and behaviorally distinct from their genetic parents.
The book serves as a valuable reminder that, like people, our pets are far more than the sum of their DNA.
Making sense of dogs
What is an anthrozoologist, anyway? Turns out it’s someone who studies human-animal interactions, and John Bradshaw, who directs the world-renowned Anthrozoology Institute based at the UK’s University of Bristol (and founded it at the University of Southampton), is pre-eminent among them. For more than a quarter of a century, he’s investigated the behavior of dogs and their people, and his findings have been widely published. In Dog Sense — his best-selling, recently released book — he expands upon his belief that “the future of the dog does not lie simply with the blunt instruments of legislation and regulation, but with better public understanding of what dogs actually are, their needs and wants.” Recently, Bradshaw shared his thoughts on evolution, training (debunking the myth behind the “dog as wolf” model), changes in breeding practices in the UK and what lies behind dogs’ attraction and attachment to us, among other intriguing ideas.
Bark: Why do you think that a proto-dog — a transition from wolf to dog — evolved?
John Bradshaw: My theory — and I have nothing to back it up — is that something happened in the brains of certain wolves that made dual socialization possible. Humans developed a propensity to take in pets, and then these particular wolves came along — these would be the protodogs. They would have looked exactly like wolves. This was not an intervention on our part, but rather, a very different cultural environment.
B: Most researchers refer to domestication as a one-way street. Didn’t other species, including the wolf and proto-dog, also have an effect on our own evolution?
JB: Domestication was a long and complex process; speculatively, I would [say] that there were several failed attempts. Researchers who are studying human evolution and the human brain pretty much say that our own evolution — at the genetic level — wasn’t influenced by dogs. But, of course, our culture has been profoundly influenced by them.
B: Do you think it’s possible that we hunted together, or perhaps learned or honed our own skills by watching wolves hunt?
JB: I don’t think we were hunting partners, to begin with, but one of the versions of human evolution that I strongly subscribe to comes from Steven Mithen, a cognitive archaeologist and professor of early prehistory, who studies the evolution of the human mind and why we are different from the Neanderthal — why they died out and we didn’t. One of the key [dissimilarities] he points to is our ancestors’ ability to think like animals. They could put themselves in the place of an animal — that they, in fact, had a connection to the animals. So we would be able to think, “If I were a wolf, what would I be doing?” or, “If I were a deer, what would I do now?”
B: If scientists have concluded that wolf behavior is different from that of dogs, why do people still consider the lupomorph (wolf pack) model as a determinant of canine behavior?
JB: They have a good excuse, which is that in terms of their DNA, dogs and wolves are so similar. However, that doesn’t mean there is similarity in their behaviors.
B: If the wolf model isn’t appropriate, what is?
JB: The behavior of feral, or village, dogs in Italy, Russia and India has been studied recently, and results show that those dogs are much closer to the ancestors of pet dogs than wolves are. These are urban feral dogs, high-density dogs, dogs in large groups. Earlier studies [of feral dogs] were conducted in environments in which the dogs were being persecuted and are like the early captive-wolf studies: not reliable.
B: You write that there is little evidence that hierarchy is a particular fixation of dogs — that dogs do not want to dominate us — but so many trainers (including Cesar Millan, as you note in the book) and others use this construct to explain dog behavior. Why is this wrong and what are its implications?
JB: Part of the problem is that confrontation makes good television, and attracts programmers, but having a confrontation in your living room with your own dog isn’t the best way to train a dog. The more effective way is to use reward-based training, which can be (by television standards) incredibly dull, since it may take hours or sometimes weeks. My colleagues and I are appalled by the popularity of this style of confrontational dog training. I don’t know what the situation is in your country, but in the UK, we have a new Animal Welfare Act, and that kind of training goes against its recommendations. The law reads, “All dogs should be trained to behave well, ideally from a very young age. Only use positive reward-based training. Avoid harsh, potentially painful or frightening training methods.”
B: Have you seen any changes in breeding practices in the UK as a result of the BBC’s “Pedigree Dogs Exposed” documentary?
JB: The genetic isolation of breeds has brought about a dramatic change in the canine gene pool. Three inquiries have been commissioned: one by the Royal Society for the Prevention of Cruelty to Animals, another by the government and a third by the Kennel Club itself, but there is still a great deal to be done. There are problems implementing the studies’ conclusions because the KC, like the AKC, is a federal structure made up of individual breed clubs. The federation has no power to tell the member breed clubs what to do.
B: Many people use puppy testing to predict a dog’s adult character. Do you feel this is valid?
JB: Dogs are born to become friendly toward people, a process that starts in about the third week of their life and goes on for several months. This process of socialization is well charted. At 16 weeks, the window of socialization to people begins to close, though it stays open a bit longer for socialization to other dogs.
B: You write that dogs have been so heavily selected to form strong attachments to humans that many suffer from separation anxiety — up to 50 percent of Labs bred in the UK, for instance. On what is this finding based?
JB: It comes from my own research and that of others. We concluded that many dogs experience this anxiety at some time in their lifetime. In one longitudinal study, we followed puppies, 40 in all, litters of Labradors and Border Collies, from eight weeks to 18 months old. Over 50 percent of the Labs and almost half of the Collies showed some kind of separation distress. Subsequent studies, during which we filmed dogs left alone, showed that self-reporting by owners underestimates the scope of the problem.
B: One of the most controversial positions you take is that being in a shelter may damage a dog. Was consideration given to contributing factors such as the length of time spent in a shelter, the condition of the facility, the interactions a dog has with other dogs and humans there, and the dog’s personality and history?
JB: We want to understand what is going on inside these dogs, and I am not in any way blaming rescuers or shelters. Dogs who have been attached to a family may suddenly wind up in a shelter for a variety of reasons: family breakup, job loss or the dog’s behavioral problems. Dogs will be very upset by this and when they arrive in a shelter, their cortisol level [a stress-related hormone] goes sky high. We know this because when we’ve taken urine samples, we’ve had to dilute the urine to even get a measurement — it was that high. They don’t have the resources to cope and go into hyperdrive, desperate to please people. As a result, in a shelter setting, dogs actually can be easily trained.
B: Dogs clearly love us, and demonstrate that in many ways, but is this what motivates them to obey us and follow our lead?
JB: Human contact has a high-level reward value for dogs; simple attention from us is rewarding. And if that attention comes while playing with them, it can be a double reward. You can train a dog with a tennis ball, but while the game is important, it is not the only thing. The real treat is the interaction. Withdraw your attention, ignore the dog, and the dog will find this withdrawal of attention aversive.
Dog's Life: Lifestyle
Study finds humans responsible for barking
Since I share a home with two Shetland Sheepdogs, barking is a part of my everyday life. While I enjoy hearing all the funny noises my pets make, barking can have serious consequences: It is one of the behavior problems that lands dogs in shelters. Ironically, humans may be responsible for the very barking we complain about.
Csaba Molnar, a former ethologist at Eotvos Lorand University, has been studying how barking evolved in the dogs we love. Barking is common in domesticated dogs, but not wild dogs.
Since barking is common in domesticated dogs, but not wild dogs, Molnar believes that the behavior is linked to selective breeding by humans. Molnar's studies have uncovered some interesting findings.
Molnar is currently seeking funding to explore why humans might have selected for barking abilities, although another theory believes that it wasn't intentional. Eugene Morton, a zoologist and animal communication expert at the National Zoo, believes that in selecting for “friendly traits” in wolves, barking was a unintended byproduct. Barks are used by juvenile wolves, which also share many other traits with domesticated dogs, such as playfulness.
No matter how barking evolved, it's pretty cool that Molnar's study showed that we can understand dogs' vocalizations to some extent. We are closer to our pets than we think!
News: Guest Posts
They’re not so different than cats after all
I love research that reveals surprising similarities between species, especially species often depicted as rivals. Last year, when MIT researchers “discovered” cats had a sophisticated and speedy mechanism for drawing fluid into their mouths, which was one reason they aren’t as sloppy as canines, it just seemed like one more example of the old cats are sleeker, neater, smarter argument.
The thinking was that dogs scooped fluids into their mouths with a backward-curled tongue action. But thanks to weirdly-watchable x-ray videos of dogs drinking, Alfred Crompton and Catherine Musinsky have revealed the dogs do lap like cats. (“How dogs lap: ingestion and intraoral transport in Canis familiaris” published in The Journal of Royal Society Biology Letters—abstract free; fee for full report.)
Both dogs and cats use a method called adhesion. “Liquid is transported through the oral cavity to the oesophagus, against gravity, on the surface of the tongue as it is drawn upwards, then a tight contact between the tongue surface and palatal rugae [ridges on the roof of the mouth] traps liquid and prevents its falling out as the tongue is protruded.”
According to a story on Wired’s blog, the commonality goes back to a shared ancestor 43 million years ago. Since that time neither cats nor dogs evolved the thick cheeks now present in many other animals, including humans. “Such cheeks form a tight seal that both retains liquid and allows suction-powered drinking. Without them, cats and dogs needed to develop a different way to drink.”
While the research could impact robot design, it probably won't improve cat-dog relations.
Dog's Life: Lifestyle
A new study of canine locomotion
Many studies of locomotion in dogs focus on sick dogs while others focus on particular aspects of locomotion. The recently published book Dogs In Motion includes the comprehensive findings of a study of more than 300 dogs and how they move. More than 30 breeds were studied with several techniques helping reveal how dogs move.
Researchers Dr. Martin Fischer and Dr. Karin Lilje used high-speed x-rays as well as infrared imaging based on reflective dots positioned on the dogs to record details of their movements from both the side and from the front. Interestingly, researchers found that no matter what breed of dog was looked at, the patterns of movements match. Though the gaits of many breeds may appear quite different, the underlying motions of bones, muscles and connective tissue are not so different after all.
The study shows that displays and textbooks sometimes have errors, particularly related to the heights of corresponding parts of the front and hind limbs. The shoulder blade and hip are often depicted at the same level, when the true placement of these joints is actually different. The thigh and the shoulder blade correspond, as do the upper arm and the lower leg. According to Fischer, the shoulder blade and forearm are moving in matched motion with the thigh and middle foot, even though that is different than what was previously thought.
Previous investigations into the ways dogs move, such as Rachel Page Elliot’s Dogsteps, have changed what people thought they knew about canine locomotion, and this most recent study is one more scientific study that does so.
Dog's Life: Lifestyle
Who is peeing and where?
Urine marking in dogs is a well-known behavior in the sense that everyone is aware that it happens, but it is poorly known in the scientific sense because so few studies have examined it with a rigorous approach.Scientists Anneke Lisberg and Charles Snowdon applied such needed rigor to the subject and report the results in “Effects of sex, social status and gonadectomy on countermarking by domestic dogs, Canis familiaris,” which was recently published in the journal Animal Behavior. Countermarking behavior in dogs consists of either marking on (overmarking) or near (adjacent marking) previous scent marks. Part of what’s so great about this study is that it shows that what we think we know about behavior from observing it casually, even over years and years, may not be as spot on (so to speak) as we think. As is so often the case, a controlled study of the relevant variables revealed that what is going on is significantly more complex than previously believed. Lisberg and Snowdon’s study is one of a few to examine canine urine marking and as such makes a big contribution to our understanding of this behavior. Here’s what their study found: In an experiment with urine from groupmates and from unfamiliar dogs presented to dogs in a controlled way on sticks, they found that: Intact males (but not neutered males) were more likely to overmark urine from intact females. Males who overmarked had a higher tail base position (which the authors used as a measure of social status) than males who did not overmark. Familiarity with a dog did not affect overmarking of its urine, but dogs adjacent-marked only urine samples from unfamiliar dogs. Neither sex nor tail base position affected adjacent marking. Being spayed or neutered had no relationship with the likelihood of countermarking. In observations of countermarking at a dog park, they found that: Males and females both countermarked and investigated urine. Males and females with higher tail base positions did more urinating, countermarking, and investigating of urine than members of their same sex with lower tail base positions. Lisberg and Snowdon conclude that although intact males may be overmarking intact female urine as a form of mate guarding as has long been suspected, that is only a piece of the story. Both sexes, whether intact or not, appear to countermark in a competitive manner. Additionally, this study suggests that overmarking and adjacent marking may have different functions. What have you observed about your dog’s marking behavior?
News: Guest Posts
C.D.C. study: Pets can be dangerous bedfellows.
Why does someone always want to rain on the parade? Here are countless people and pets—my household very much included—enjoying perfectly wonderful and healthy nights together, when some buzzkill at the Centers for Disease Control and Prevention starts throwing around zoonoses and pathogens, even bubonic plague!I read about the C.D.C study warning about the risks of pets in your bed in The New York Times and wondered, don’t these researchers have anything better to do? I can’t believe that the “risks” outweigh the emotional and physiological benefits of keeping our pets close. I’m all for precautions, as much for my dogs as for me. No fleas or ticks allowed. No licking wounds. No biting. No open-mouth kissing. If anything worries me, it’s the sleep I lose on nights when the dogs are stealing the covers or inching too far into my real estate. For that, they get kicked to the curb.
Dog's Life: Lifestyle
What does it mean?
A graduate student studying the diet and nutrition of people living in Texas between 1,000 and 10,000 years ago has found evidence that those people were eating dog meat. Samuel Belknap III was sorting through dried human waste and found a bone that DNA tests suggest came from a domesticated dog, not a fox or wolf. The bone was found in a pile of human excrement and had the orange-brown color typical of a bone that has passed through someone’s digestive tract, which is why the reseachers think their find shows that people were eating dog meat.Although it is unappealing in our culture to eat dog meat, especially among dog lovers, it’s really not so surprising that people in Texas thousands of years ago were doing so. In Central America during that time period, many people ate dogs, and across the Great Plains, many people did so when food was scarce. Eating the meat of dogs is widespread today, though it is not common in Western culture. Additionally, many of us who cringe at the thought of dog meat do eat the meat from other domestic animals such as cows, sheep, goats and chicken. Carbon-dating suggests that the bone in question is 9,400 years old, and thus is the oldest evidence of domesticated dogs in the Americas. The next oldest finds were of dogs from around 8,000 years ago. Evidence of domestication from archaeological records goes back over 30,000 years in Belgium, 26,000 years in the Czech Republic and as far back as 15,000 years in Siberia. On this side of the Atlantic, the records are less detailed and do not extend as far back as in other areas of the world. There are some concerns regarding the study such as the possibility that the dog was consumed by some other animal other than a human, and that the DNA testing on such a small bone fragment may not be accurate. The piece of bone is 15 millimeters by 8-10 millimeters, which is roughly the size of a pinky fingernail. The bone has been identified as a fragment from where the skull and spine connect. The full article on this discovery will be coming out in the American Journal of Physical Anthropology later this year.
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