News: Guest Posts
Explaining a Seeing Eye dog’s vision to children
Whitney and I visited a school on the North Side of Chicago recently, and for some reason the first and second graders seemed particularly interested in color blindness. When one of them asked me if it’s true that dogs can only see black and white, I explained that dogs do see some colors, but they can’t tell the difference between red and green.
“If we’re at an intersection with a stoplight, it’s my job to judge when it might be safe to cross.” I described the way I stand up straight, concentrate and listen for the rush of cars. When it sounds like the traffic is going the direction I want to go, I take a guess the light is green and command Whitney to go forward. Whitney’s ears perk up; she listens for traffic and looks left and right to confirm it’s safe before pulling me across.
The students seemed satisfied with that answer and went on with other questions. Are you blind all of the time? When you were at the Seeing Eye school, what was your teacher’s name? Does Whitney like to lick a lot? What do you and Whitney do to have fun? Their thoughts eventually returned to colors, though.
One girl told me that her school uniform is red. “But does Whitney think they’re green?” I gave that question some thought, and realized I couldn’t answer it. When I got home, I did some research.
Dogs see colors, but not the same way humans do. People can see variations of violet, blue, green, yellow, orange and red. Dogs can only see blue, violet, yellow and some shades of gray.
My source? An article in the Journal of the American Veterinary Medical Association called “Vision in Dogs,” written by P.E. Miller and C.J. Murphy. A credible source, but not sure it answers this sweet first grader’s question.
If dogs can’t see the color red, what do they see instead? Blue? Violet?
Yellow? If any of you blog followers have an answer, by all means leave a comment. I’m curious to know now, too!
Dog's Life: Humane
The many sides of temperament testing
In a gathering storm centered on the policies of animal shelters, temperament testing has become a lightning rod. Some resource- and space-starved shelters—which might have once chosen dogs for adoption based on such specious criteria as color, size, age, breed or length of time in the shelter—now use a series of tests that purport to evaluate a dog’s behavior and predict whether the dog will be a good companion for an adopter. Shelters using such tests make several claims for doing so: The dogs they put up for adoption are safer; dogs are selected based on whether they would be good family pets without regard to age or appearance; data gleaned from the tests help shelters find better adoption matches and provide useful information to adopters; and as a result, more people in the community are adopting shelter dogs.
So what’s prompting the firestorm? Several issues. No one advocates putting vicious dogs up for adoption, but many people think good dogs are being declared unadoptable because the tests are unfair and the people administering the tests are not qualified. A common refrain is, “My dog wouldn’t have passed the test.” Further, opponents of temperament testing claim shelters use these tests to hide the truth—that they show low euthanasia rates and high adoption rates by counting only “adoptable” dogs (those that passed the test). This, they believe, deludes a community into believing that there’s no pet over-population problem, and encourages people to drop off an inconvenient dog at a shelter. Detractors also claim that testing tempts shelters to focus on quick resolution rather than spending in-house resources on prevention and utilizing outside resources such as rescue groups.
Central to all these important and intense issues, though, is the fundamental question: Are temperament tests valid? That is, can testing a dog in a stressful shelter environment predict later behavior of the dog?
Most people advocating tests agree that “temperament” tests, in fact, are not valid because a dog’s “temperament” is subjective. Instead, they prefer calling the tests “behavior evaluations,” because behavior can be seen and described objectively. Two such behavior evaluations, Sue Sternberg’s Assess-a-Pet and Dr. Emily Weiss’ SAFER/Meet Your Match, are the ones most likely to be used by shelters because information about these tests is readily available through workshops, seminars, books, and videos as well as from such organizations as the American Humane Association and the American Society for the Prevention of Cruelty to Animals (ASPCA).
“The purpose of the test is to find the gems that don’t often come in gemlike packages,” Sternberg says. “I wanted to develop a test that would reveal what the dog would be like with the average adopter, not with a professional dog trainer.” It begins with hands-off observation in which the tester looks for sociable or nonsociable responses, and progresses to evaluations for play, arousal, resource guarding, behavior with cats and mental sensitivity. The test uses the infamous Assess-a-Hand, an artificial hand on a stick that allows someone testing for resource guarding to safely approach, pet and then try to pull a food dish or chew toy away from a dog. Among other recommendations, Sternberg advises shelters to wait two to four days before testing and have two trained people perform the test.
Assess-a-Pet is not a simple pass/fail test; in most parts of the evaluation, the tester selects among a range of responses and also adds observations. For example, the four responses to a test during which the tester strokes the back of the dog are: moves toward tester in at least two out of three strokes, stays in same spot, moves away from tester, or freezes and becomes more aroused. Although some dogs have extreme responses, most responses land in a gray area.
“Mostly, the tests give us information that helps us determine who we can put the dog with,” says Trish King, director of behavior and training at the Marin Humane Society (in northern California), which bases their behavior evaluations on the Assess-a-Pet test. “If a dog is problematic in one area but fantastic in others, we will go out of our way to place that dog because we have the room and the training facility. Unfortunately, other places don’t.” At the Marin Humane Society, virtually all dogs are held for three to four days before any testing, walked outside in a lawn area to relieve themselves first and tested in a quiet room away from the kennels by two people (one of whom has gone through a full apprenticeship program). Any dog that fails—about 5 percent according to King—is retested at least once within three days, and all dogs who show health problems are tested again once they’re healthy.
SAFER/Meet Your Match
The ASPCA in New York, which receives dogs from their humane law enforcement officers, from the NYC Animal Care & Control, and from owner surrenders, uses the SAFER test to determine whether to accept owner-surrendered dogs. “The ACC dogs that we take have already been evaluated,” says Pamela Reid, PhD, director of the Animal Behavior Center. “But for the owner surrenders, we use the SAFER test to get a quick assessment. We’ve raised the bar on which of these dogs we’re willing to accept because we already get a lot of problem dogs from humane law enforcement.” Once a dog has been in the shelter a few days, it’s given a full evaluation using parts of a 140-test-item behavior evaluation developed by Dr. Amy Marder, a veterinarian now with the Animal Rescue League of Boston. “The full test took an hour-and-a-half,” says Reid. “So, we’re using a pared-down version based on her research that includes only the parts that are predictive of behavior in the home.”
San Francisco SPCA
So, the SF/SPCA devised its own test. “We sat down with all our trainers, decided what we were going to accept or not going to accept, defined our terms, and created a test with objective scoring,” Donaldson says. “We’ve got to have an objective test or our data becomes junk.”
Instead of asking if a dog is friendly, for example, they ask if the dog approached a handler within X number of seconds; if it growled for three seconds when a stimulus was within six feet on the right side; and, as the stimulus came closer, did the dog snap or continue to growl. “We’re checking boxes and at the end we can see if the dog is above or below our criteria for an adoptable dog,” says Donaldson, who notes that dogs often pass the test with suggestions for behavior modification. “Because the criteria were agreed upon by all people in the shelter, and the result is the same whether I test, you test, the test happens this week or next week, no one is forced into a god position.”
To determine reliability, they tested their method in two ways: The dog was retested (without behavior modification) a week later by the original tester and the results were com-pared; and three to five testers tested the dog independently and those results were compared. Because results were the same, the test was deemed reliable.
As for valid? “We keep records on all the dogs, but what has to happen and has not happened is the follow-up,” Donaldson says. “The issue with our test and with all the evaluations is that we haven’t crunched enough follow-up numbers. We have to say we really don’t know.”
Some data on temperament tests is slowly becoming available, though.
Testing the Tests
She has also begun evaluating dogs in boarding kennels to see whether the tests are as valid for dogs with homes as for dogs in shelters. “On dogs already in loving homes, SAFER is proving to be predictive of aggression and nonaggression,” she says. “While we are still collecting and analyzing the data, early reports indicate a strong predictability.”
In a separate study, Dr. Marder has been looking at the results of follow-up phone surveys for 70 adopted dogs that were assessed at the ASPCA using her 140-test-item behavioral evaluation. “I was seeing dogs put to sleep that were like dogs in my private practice,” she says. “The owners were working on the problems and the dogs were doing fine. So, I wanted to find out which tests in the behavioral evaluation were predictive of behaviors in the home.”
Each test-item in the evaluation called for objective observations: Evaluators described the placement of a dog’s ears, for example, rather than classifying a dog as “happy.” And, the evaluation as a whole was tested and determined to be reliable: results were the same regardless of who did the testing.
To organize the study, Dr. Marder grouped the test items into such categories as possessive behavior, handling, protective behavior, cage behavior and response to fearful stimuli. The dogs’ responses were also categorized by such behavior as aggressive, friendly and fearful. The phone surveys made one, two, three and six months after adoption asked about these categories.
In “Pick of the Shelter,” (Bark, Fall ’03) Patricia McConnell, PhD, wrote, “It is impossible to perfectly predict the behavior of a dog in one context when you’re doing the evaluation in another. Period. End of sentence. Impossible.” Dr. Marder’s results show that this statement is true.
Rather than trying to draw a perfect correlation between a shelter test and behavior in the home, Dr. Marder decided to look at how well (how perfectly) a test predicted behavior, in the same way, for example, that results of an SAT test predict academic success or failure.
Once her numbers were crunched, she concluded that none of the individual test items were 100 percent predictive; each test only indicated tendencies. She also determined that the ability of any test to predict behavior changed over time. “The dogs change in two directions, an increase in behavior or decrease in behavior,” she says, and recommends that other information, such as intake profiles and the behavior of the dog in the shelter, also guide predictions and triage decisions.
With this in mind and looking at the broad picture, Dr. Marder’s analysis shows that if a dog growled, snapped or bit during any test in the shelter evaluation, the dog was more likely than not to exhibit one of these behaviors again after adoption. But, importantly, by digging deeper into the numbers, she saw that growling during any test at the shelter did not predict snapping or biting after adoption.
When considering categories of behavior, she found three for which positive tests were moderately predictive: possessive aggression, protective behavior and mouthing. That is, if a dog lifted a lip, growled, snapped or bit over food, rawhide or a bed during the test, the dog was likely to show some form of possessive aggression after adoption. Similarly, dogs who lifted a lip, growled, barked, snapped or bit when approached or threatened by a stranger (protective behavior) were likely to show territorial behavior after adoption. And dogs that mouthed during the test were likely to mouth after adoption.
Somewhat predictive were positive responses in categories having to do with aggression to children (dogs were tested with a toddler doll), interdog aggression and separation anxiety. And if a dog showed cage aggression in the shelter, it was somewhat likely to exhibit territorial behavior after adoption.
Of course, what the dog doesn’t do during an evaluation is also important. For example, dogs who did not show possessive aggression, separation anxiety or fear of people during the test were not likely to have these behaviors pop up after adoption, either. And a dog’s friendliness, or lack thereof, in the shelter tended to be the same after adoption. The number crunching continues as she readies the data for publication.
For her first study, Smith tracked 839 behaviorally assessed dogs adopted over a two-year period. The results, which she’s planning to present at the HSUS/Animal Care Expo in March, show that dogs put into a level-one category (no restrictions) after the behavior assessment stayed in the shelter an average of six days, level-two dogs (restrictions such as homes with older children) stayed an average of nine days, and level-three dogs (more difficult issues) stayed 14 days. Some of the level-one dogs were returned and adopted out again, but none were euthanized. On the other hand, 3 percent of the level-two dogs and 7 percent of the level-three dogs were returned and euthanized (or euthanized elsewhere) for behavior problems. “Our return rate has decreased since implementing an assessment process,” she says. “We are making better matches and our euthanasia rate has not increased.” Smith believes that because of temperament testing, the shelter is putting safer dogs up for adoption.
Bollen tracked 2,017 dogs that she tested personally with Assess-a-Pet using follow-up calls at six months for every dog and at one year for random dogs. “I tried to do as many components of the test as I could, whether or not the dog was aggressive during the test,” she says. Bollen, who hopes to have her results published in a peer-reviewed journal, was unwilling to release actual statistics at this time, but did share some general results.
“I found that if a dog showed overt aggression that caused it to fail one part of the test, it was likely to show overt aggression in other parts of the test,” she says. And, of the dogs she deemed adoptable, a high majority showed no aggression after adoption. “My results show that the temperament test does identify dogs that have a tendency to exhibit aggression in certain situations. Performing the test reduces returns because we reduce the number of aggressive dogs who are placed back into the community, and it allows us to make better placements. And, lastly, borderline dogs, the ones that showed behaviors of concern during the temperament test but were adopted out, were more likely to exhibit behavior problems or aggression post-adoption.”
The results sound encouraging; however, canine behaviorist Dr. Karen Overall, who is on the faculty of the University of Pennsylvania’s School of Medicine, casts a skeptical eye on temperament testing and the data being presented. “I think Amy Marder’s work has a lot of potential because she’s asking about probability, about how consistent the dog’s behavior is over time,” she says. “I’m a scientist. Before I can look at findings, the test has to be repeatable and reliable and there has to be objective criteria. We have to codify the behavior … where the dog’s ears are, if there’s vocalization, and if so, whether it starts low and goes up or goes down, where the feet are, what the hair is doing. And context matters. The people who use the Assess-a-Hand do so to have a safe way to reach toward the animal, but the first set of conditions is whether your test instrument is valid. This test object doesn’t mirror the real world, so the answer has to be no. So, don’t tell me a dog growled.
“I’m not saying there aren’t factors in these tests that will be predictive, but they may not predict what people think,” Overall adds. “When I review the tests, I see spurious correlations.”
Dr. Overall isn’t alone among behaviorists in questioning the tests. “We do our damnedest to find appropriate placements,” says Reid. “The test gives us just one snapshot of behavior. We’ve had dogs that aren’t good on the evaluation but were fine with the people who were walking them and cleaning the cages. So we take that into consideration.”
Reid joins her colleagues in calling for more research. “The two things that are missing are, first, more studies and greater numbers,” she says. “And second, we need information about dogs that fail an evaluation in some way, undergo rehabilitation and get adopted out. We need to know whether the behaviors resurface.”
Adds Donaldson, “The anti-testing people are so incredibly well-meaning. I know where they’re coming from. You run a test, adopt the dog anyway, and the dog is fine. Clearly there are problems with the tests, but it could be that some tests are valid, that some parts of the tests may have good predictive value. The preliminary results from tests by Emily [Weiss] and Amy [Marder] have value and are a tantalizing reinforcement for some things, but we have to get funding for more research. Before we can save all the dogs, we have to triage; we have to save the maximum number of dogs in a way that makes sense. If testing is not the way, if it turns out that there is no way to test that’s adequately valid, then we’ll need to stop banging our heads on the testing wall. But then what will we go on?”
Implicit in the work these researchers and behaviorists are doing and in the worries people inside and outside the shelter system have about temperament testing is their concern for the community and for the dogs. Pete Miller, a shelter supervisor at Santa Barbara County Animal Services and a 20-year veteran of the shelter system who believes temperament tests are a necessary part of good sheltering practice, perhaps puts this best: “When a dog dies in an animal shelter, it almost doesn’t matter whether the dog was an old favorite or a hopeless case of a violent animal that never had a chance; the dog was alive one second, and literally gone the next. Everything it ever was and every possibility for what it would have been and done—gone in a second. It’s the actual fact of the real loss and what it means to kill that needs to weigh most and is the reason there should never be a formula that tries to remove the responsibility from a person or dim the reality of what it means to take away a life.”
Editor's Note: This article won the 2004 ASPCA Humane Special Award for Dog Writing.
Dog's Life: Lifestyle
Dogs understand pointing better than chimps
A few years ago I took my dogs to the Harvard Canine Cognition Lab to participate in some really interesting research. One of the studies looked at the dogs' understanding of gestures, such as pointing. I didn't think my pups were really making the association in the lab, but at home I do think that they seem to understand when I'm pointing at things. Maybe it's just a shared understanding we've developed after years of living together.
Despite my anecdotal findings, apparently dogs are pretty good at understanding gestures. Previous studies have shown this before, but recent research shows that dogs are even better in this area than chimps.
A team of researchers at the Max Planck Institute for Evolutionary Anthropology in Germany presented 20 chimps and 32 dogs with the same task, retrieving an object that a researcher pointed to. The team found that the dogs were much more successful than the chimps.
The researchers think that pointing may be a human form of communication, which is why the chimps couldn't understand the concept. However, they were puzzled by the fact that the dogs were able to pick up on the pointing.
I wonder if this has to do with the close relationship we have with our dogs. They've evolved around humans and previous studies have shown that they can understand our body language. It's a pretty cool concept!
News: Guest Posts
Points to more than one common ancestor
A well-preserved skull discovered in a cave in the Altai Mountains of Siberia has been identified as the 33,000-year-old remains of a domesticated dog—making it among the oldest evidence of domestication, according to a report originally published in Plos One.
The discovery means the story of domestication as happening in a single place needs to be revised. It looks very much like domestication happened repeatedly in different geographic areas and who knows how far back.
Although the shortened snout and widened jaw in the Siberian skull offer clear evidence of domestication, this dog is not an ancestor of the modern dog. Nor are equally ancient dog remains discovered earlier in a cave in Belgium. These lines appear not to have survived the last great ice age (which began about 26,000 years ago).
I’m intrigued and excited by the idea that humans were living with dogs—for protection, companionship, help on the hunt—not just in many places but well before other animals were domesticated for agricultural use. The science continues to make the case for a very deep relationship.
News: Guest Posts
In-home DNA tests are cheaper. Are they better?
Just in time for Christmas, the Canine Heritage Breed Test came out with a 4th gneration test to look for evidence of 120 breeds in your dog’s DNA, for the rock-bottom price of $25. Honestly, that seems like a pretty good deal—as long as you don’t plan on taking the results too seriously. I know of what I speak.
In 2007, the first in-home genetic tests started making the rounds. I wanted to unlock the nuances of my mutt, who was best described as a Labrador Retriever/Husky mix (See Lulu, left). So I sent a cheek swab along with $65 to MMI Genomics (creators of the Canine Heritage test).
I got a call, instead of the promised heritage certificate. Turns out, Lulu didn’t match with any of the then-38 breeds in the test. The results showed a little Siberian Husky “in the mix,” along with Chow Chow, Chinese Shar-Pei and Akita—none of which were “statistically significant” or made much sense.
MMI offered to refund my money and to flag Lulu’s sample for the next generation of testing in a few months, which aimed to include around 100 breeds. I wrote a blog about how I was relieved not to know, embracing the mystery, yada, yada, yada. Meanwhile, true to their word, the folks at MMI retested Lulu a while later. This time she came in with no “primary” matches, and Labrador Retriever as a “secondary” match and Yorkshire Terrier “in the mix.” Yorkie? Seriously?
Even though I repudiated any need to know by this time, I jumped onboard when Mars Veterinary launched its Wisdom Panel DNA test, based on blood samples drawn by your vet. Clearly, I wanted to know, and somehow not being personally responsible for collecting the testing sample made me more confident about the results.
The cost: I don’t actually remember, but significantly more than MMI’s swab test, plus the cost of the blood draw. (Now, Mars has a Widsom Panel cheek swab test as well, for $49.99).
Lulu’s Wisdom Panel found that she has some German Shepherd Dog and Labrador Retriever with a “high degree of certainty” and some Brittany with a “medium degree of certainty.” These breeds, at least, make sense to me—she looks and acts a little like all three types of dogs.
Ultimately, knowing she’s a German Labrittany didn’t change a thing about our happy life together, except I finally had an answer when strangers asked, “What kind of dog is that?” (Here’s one take on this phenomenon [video].) Worth $25? Probably.
Have you tried a DNA test for your dog? I’d love to hear about it.
Dog's Life: Lifestyle
Study finds that rats look out for their friends
Rats have a bad reputation, but they actually make wonderful pets. I had two before my living situation allowed me to welcome dogs into my family. They were clean and actually quite personable. Reggie and Angie quickly learned their names and would run to the side of the cage when I came into the room. I always thought of them as being very dog-like.
A recent study not only confirmed that rats are smart, but found that they may have empathy for their friends.
Researchers at the University of Chicago placed a free-roaming rat in an enclosure with a caged rat. Once the free rats realized that they could release the trapped rat, they opened the cage every day, even if they were immediately separated (proving the rats were empathetic and not only freeing the trapped rats for companionship).
In the final set-up, the researchers placed rats into an enclosure with two cages—one with another rat and the other with chocolate. They found that the free rats were just as likely to free the caged rats as they were to access the chocolate. Even more unbelievable, the rats almost always shared the treats with the freed rats.
Interestingly when females figured out how to open the cage, they would immediately open it every day. Male rats would occasionally take a day off.
It’s pretty cool that there’s research showing that animals aren’t always just looking out for themselves. I would love to see a similar study done with dogs. When I was checking out the Canine Cognition Lab at Harvard University, the researchers mentioned that they had a canine empathy study in the works and there are other scientists who have tackled the subject.
I do think dogs are capably of empathy, even though I’ve never seen it in my own pups. I’ve heard stories of therapy dogs that “take on” the stress symptoms of the patients they visit and pups who won’t leave someone’s side when they’re depressed.
Have you seen your pups express empathy?
Dog's Life: Lifestyle
Results look promising
For anyone whose life has been touched by cancer, and that’s most people, any advancement in treating the disease provides hope and is welcome news. A new tool that helps in the treatment of osteosarcoma is a result of Stan Stearns’s desire to help other dogs like his St. Bernard Gabriel. Gabriel was diagnosed with cancer in 2007, and succumbed to the disease in 2008.
Stearns is an entrepreneur whose company, Valco Instruments, makes tiny tools used for precision work in laboratories. He developed a small drill that can be used to deliver a tiny quantity of a radioactive isotope to a dog’s tumor. This allows doctors to target the tumor accurately without causing harm to healthy cells or subjecting the entire body to chemotherapy. Preliminary results suggest that this treatment alleviates pain and limits the spread of the cancer.
Radioactive isotope therapy is a newer treatment for osteosarcoma, which is often treated by amputating an affected leg, though the cancer still often spreads to the lungs, at which point it’s difficult for the dog to survive more than a year. Treatment for dogs can be $6,000, and Stearns’s Foundation, the Gabriel Institute, has paid the costs for some families.
The goal of the Gabriel Institute is to conduct and support research into bone cancer with the hope of finding a cure. Though the institute focuses on dogs, the hope is that the research will benefit people with bone cancer as well.
Dog's Life: Lifestyle
A study looks at the characteristics of reactive dogs
As pet lovers, we've always known that animals pick up on our emotions. When I first started competing in rally obedience and agility, Nemo always seemed to pick up on how nervous I was. As I gained more confidence, Nemo also looked more comfortable in the ring.
But could our being male or female affect our pets?
According to a new study, the sex of the person on the other end of the leash has the biggest effect on reactive behavior towards other dogs. The researchers proposed that the higher instance of threatening behavior and bites may be connected to a higher instance of aggressive and impulsive tendencies in men.
The study is certainly interesting, but there could be many explanations for this finding. Perhaps men are more likely to choose dogs that have strong personalities that are predisposed to being reactive towards other dogs. Or maybe men are less likely to socialize their pets. When I go dog events, like group hikes and play groups, the crowd is always mostly female.
What do you think about the study's findings?
Dog's Life: Lifestyle
Study: Dogs behave based on observations of people
My dogs always seem to be watching what I'm doing. I'd like to think they care about my well being, but I think they're more interested in any clues that I might drop food or that it might be dinner time.
A recent study led by Sarah Marshall-Pescini at the University of Milan looks at the information dogs get from watching us and the decisions they make based on that data. Her research focused on what's called interspecies evesdropping, one species (in this case a dog) watching the interactions between two members of another species (in this case two humans).
In the study, the researchers had dogs observe food-sharing between humans. One person, designated the “beggar,” approached two people sitting on separate chairs, both holding a bowl of sausages. When the beggar asked for a piece, one person said no and moved one hand in a dismissive gesture, and the other said “have it” and gave a piece to the beggar. The beggar then left the room and the dog was set free to make a choice.
The study found that the dogs were five times more likely to approach the person who shared a piece of sausage than the person who chose not to share.
My dogs, particularly my food-greedy Shelties, are particularly clever at figuring out who is most likely to give them food. In my house, we like to call it “identifying the weak one.” While the study didn't exactly surprise me, it's interesting that eavesdropping on third-party interactions is a quality that we share with our dogs. The information gained from eavesdropping is considered an important input for decision-making in many other animals, including humans.
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!
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