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What the Dog Knows

Scent, Science, and the Amazing Ways Dogs Perceive the World


About The Book

A firsthand exploration of the extraordinary abilities and surprising, sometimes life-saving talents of “working dogs”—pups who can sniff out drugs, find explosives, even locate the dead—as told through the experiences of a journalist and her intrepid canine companion, which The New York Times calls “a fascinating, deeply reported journey into the…amazing things dogs can do with their noses.”

There are thousands of working dogs all over the US and beyond with incredible abilities—they can find missing people, detect drugs and bombs, pinpoint unmarked graves of Civil War soldiers, or even find drowning victims more than two hundred feet below the surface of a lake. These abilities may seem magical or mysterious, but author Cat Warren shows the science, the rigorous training, and the skilled handling that underlie these creatures’ amazing abilities.

Cat Warren is a university professor and journalist who had tried everything she could think of to harness her dog Solo’s boundless energy and enthusiasm…until a behavior coach suggested she try training him to be a “working dog.” What started out as a hobby soon became a calling, as Warren was introduced to the hidden universe of dogs who do this essential work and the handlers who train them.

Her dog Solo has a fine nose and knows how to use it, but he’s only one of many astounding dogs in a varied field. Warren interviews cognitive psychologists, historians, medical examiners, epidemiologists, and forensic anthropologists, as well as the breeders, trainers, and handlers who work with and rely on these intelligent and adaptable animals daily. Along the way, Warren discovers story after story that prove the capabilities—as well as the very real limits—of working dogs and their human partners. Clear-eyed and unsentimental, Warren explains why our partnership with working dogs is woven into the fabric of society, and why we keep finding new uses for the wonderful noses of our four-legged friends.

Reading Group Guide

This reading group guide for What the Dog Knows includes an introduction, discussion questions, ideas for enhancing your book club, and a Q&A with author Cat Warren. The suggested questions are intended to help your reading group find new and interesting angles and topics for your discussion. We hope that these ideas will enrich your conversation and increase your enjoyment of the book.



Researchers have only just begun to understand dogs’ olfactory abilities. The mystery deepens with scent-detection dogs. What started as a hobby to train her unruly German shepherd puppy transformed into a passion, as Cat Warren, a science journalism professor, started to train Solo as a cadaver dog and learn about the complex world of working canines. Combining powerful storytelling with painstaking research, Warren takes us on a fascinating journey to learn what the dog knows.


Topics and Questions for Discussion

1. Why does author Cat Warren believe researchers have studied vision more than olfactory sense? Why do you think it receives less attention in the research community?

2. How do some of the training methods used for working dogs differ from training companion dogs? Do you think every dog needs a job? Why was having a job so important for Solo?

3. Both Nancy and Mike encouraged Cat to “let go” when it came to training Solo. What did they mean by this? Why do you think this is a difficult instinct to overcome?

4. How can handlers’ moods and personalities influence their working dogs? Give some examples of Solo reacting to Cat’s moods.

5. What is a “false alert”? Why do these alerts come up during training? What did Cat do to minimize their happening with Solo?

6. What techniques did Cat use to get Solo to ignore her gaze? Why was this so crucial in their detection work?

7. Why is the Winthrop Point theory important to criminal investigators and cadaver-dog handlers? How could relying on it be potentially distracting for handlers and their dogs?

8. What fine line do handlers have to tread between searching where law enforcement tells them versus following their and, more especially, their dogs’ instincts? When is it appropriate to bend the rules? When is it not?

9. Describe the differences between a traditional cadaver-dog search on land and a search on water. What scent detection skills did you find most interesting? Why?

10. Despite the technological advances of artificial noses, law enforcement continues to supplement investigations with tried-and-true working dogs. How reliable are electronic or bioengineered noses? What’s the biggest problem Cat identifies with these technological innovations?

11. What kind of challenges did Cat face juggling her academic pursuits with her cadaver-dog handling?

12. Would you train your own dog to be a working dog if you had the time and opportunity?


Enhance Your Book Club

1. Cat Warren notes the high number of unsolved missing-person cases in the United States. With your book club, select a missing-person case that’s compelling to you (from the news, a history book, etc.). Discuss whether detection dogs were used or not, and whether detection dogs might have made a difference if they had been used.

2. What research or researcher did you find most interesting in What the Dog Knows? Select a research article to discuss at your next book club.

3. Invite a volunteer detection-dog handler to your next book club. Ask that person to bring his or her dog, if possible.

4. Visit Cat Warren’s website,, to watch videos of Cat’s training with Solo, listen to audiobook excerpts, and read Cat’s blog.


A Conversation with Cat Warren

At what moment did you realize cadaver-dog training was going to become a central part of your life?

There wasn’t one “Wow, this is so cool” moment. Instead, it was cumulative, a series of small steps where I turned around, looked back, and realized how far I’d come with Solo—and how much fun I’d had along the way. It wasn’t just me. The work made Solo happy, too. I expect Solo and I share some of the same reasons for loving this work: We like the woods. We both share a desire to get to the source of whatever it is we are looking for. We like to be acknowledged and rewarded for that work. For Solo, that’s his tug toy and my telling him what a fine dog he is. As for me, I like mysteries to be solved.

If Solo had been born with siblings, do you think he would have evolved into the cadaver dog he is today? How do you imagine things would have been different?

Solo would have been as capable of being a cadaver dog without having been a singleton. Being an only pup didn’t give him his drive and good nose. But I doubt I would have trained him to be a cadaver dog if he hadn’t had issues with other dogs. He would have been a great companion dog, but I wouldn’t have pushed to find something for him to do. In retrospect, I’m grateful that he was such a jackass.

Do full-time working dog handlers exist within detection work?

The world of working canines is huge and complex. Many law enforcement departments have full-time K9 handlers. A number of police departments have dedicated bomb- and explosives-sniffing dogs, who do nothing else. Or dogs whose only job is to sniff out currency because there are large ports and airports nearby. A handful of police departments nationwide still have full time cadaver-dog handlers. But departments make hard choices depending on their needs. Mostly, they don’t need a dedicated cadaver-dog team. That’s why well-trained volunteer units fill such a need. And I’m so happy to be a volunteer.

Would you have ever used Solo in another kind of work, such as a therapy dog?

Let’s face it: He’s a great therapy dog for me, but Solo’s personality wouldn’t make him a good therapy dog for others. Calm and quiet usually wins the day for therapy dogs. Even as an adult, Solo is like a baby rhinoceros who doesn’t always realize he’s mowing things down. I shudder to think about how he might inadvertently harm a patient with his enthusiasm. I have great admiration for people and dogs who visit nursing homes and hospitals, but Solo would be evicted instantly because of the noisy ruckus he can’t help making.

In Chapter 10, you discuss “bullshit” and some handlers’ refusal to acknowledge false alerts. Do you consider false alerts inevitable?

All handlers want their dogs to do an amazing job and never “false alert”—that is, indicate something is there when it isn’t. But for dogs to work at the peak of their ability, they have to be constantly challenged during training—and that means making mistakes. Good trainers try to create scenarios where either the dog or the handler will make a mistake because they are being faced with new scenarios. Let’s face it: No dog and no handler is perfect. I don’t think that false alerts are inevitable, but I do think that failure is inevitable. That’s how you and your dog learn. An occasional false alert is part of training hard and pushing the dog and yourself.

When it comes to dogs working independently and “ignoring their handler’s gaze” and influence, are some dogs more prone to ignoring the gaze? How much does the dog’s personality, like stubbornness, factor into it? What about breed?

Learning to ignore the handler and work independently doesn’t necessarily depend on the breed. It’s more about the particular dog, the training it has, and the dog’s relationship with the handler. In some ways, getting a dog to ignore his handler and do his work can have more to do with the handler than with the particular dog. One experienced handler sent me a wonderful e-mail after she read the book. She finally realized why her second search dog didn’t work independently: She was so used to training other handlers and explaining things that she was talking constantly while she was working her own dog. The dog, she said, was completely distracted by her chattering. So she tried, in Nancy Hook’s term, “zipping her lip.” It worked. The dog performed beautifully and independently, she wrote.

What was the most difficult case you worked with Solo? Have any cases impacted you long-term?

I don’t write at length about specific cases in the book, except for one, because the majority of cases are part of ongoing legal proceedings. But every case is difficult and haunting in its own way. I still think about a number of searches that Solo and I went on. I even think about some  that I never went on but know about. Some cases stay with me because of the perpetrator’s brutality and indifference to the victim’s suffering. Some haunt me because they were so avoidable and sad. And some cases that touch me aren’t even cases, but part of our more distant past. Watching Solo or other dogs try to locate the remains of slaves and soldiers makes me think about the history of this country in ways I never have before.

On average, how often do authorities require dogs who can search for bodies underwater compared with traditional detection scenarios? Is it worthwhile to train a dog in both techniques?

I don’t know how often authorities request cadaver dogs trained for water. There’s no tracking mechanism for that. Many times, though, authorities don’t even know that some trained cadaver dogs are also trained to work in water. It’s an important part of educating law enforcement and rescue officials. It’s very worthwhile to train a cadaver dog in both techniques. Cadaver dogs with good water training can be enormously effective in helping pinpoint or narrow down the location of a victim in water—in ways that radar or other tools cannot.

Would you ever consider handling a dog for military purposes? Do you think Solo would have been suited for it? What about Coda?

I personally wouldn’t consider it, although I greatly admire people like Kathy Holbert and Matt Zarrella who took their dogs to Asia and the Middle East to search for the missing. It’s interesting to imagine the different reactions of my two dogs to the challenges of a conflict zone. Solo might find it stressful, just as I would. Coda might thrive in such a situation; she has a number of different gears, some of which I’m just learning about. She’s perfectly at home with chaos, loud sounds, and new environments. “Bomb-proof ” is an apt term for little Coda.

How do you cope when you’re waiting for a call that never comes? How much did this type of waiting affect your other job?

I make sure my search gear is packed and ready to go. My university work has its own schedules and demands: If students are sitting in a classroom, that’s where my attention and focus go. In some ways, the juggling has made me more efficient. That’s what I tell myself, anyway.

How much do you consider detection-dog handling as part of your identity? Do you see yourself doing it for as long as you can?

I mostly don’t live life with regrets for roads not taken. But I sometimes wish that I were twenty years old, with the possibility of decades of working dogs still in front of me. I came to this late, but I was so lucky with Solo. He gave me this new identity, which feels like an integral part of me. Now, I want to do it as long as I can. I know people who are in their seventies working dogs. They are my inspiration.

Despite the tools and technologies developed for detecting specific scents, authorities continue to rely on dogs’ noses. Do you think technology will ever advance beyond that?

Technology can always surprise us. When I wrote about artificial noses, I didn’t know what I might discover. I’m a reporter, and while I have my personal preferences, I didn’t go into the research thinking the dog’s nose was inevitably superior to what science and technology might offer. For certain purposes, artificial noses are a better choice. But dogs still rule in so many arenas where we need their noses, fine judgment, and adaptability. Tomorrow, a new technology may emerge that does a better job in finding dropped weapons or helping narrow the area of a drowning victim. But dogs, too, can surprise us. We continue to make strides in how effectively we understand, train, and handle working dogs.

What advice would you give to someone interested in becoming a handler for a cadaver or detection dog?

Do it! Find the people who can help you, find the dog who will help you along the path. Don’t do it because you think it’s a public service or because you think the world needs more volunteers out looking for the missing. Don’t do it because you think you’ll become indispensible. Do it because it’s a wonderful way to be with a dog and a wonderful way to learn about the world. I feel so lucky to have stumbled upon this work, but there are hundreds of different ways to partner with dogs.

Does Coda seem better suited to a certain kind of cadaver work compared with Solo? What are the biggest differences between them?

Coda is young and has so much to learn. The differences between her and Solo are significant: She is still less bonded to me than Solo is, but that’s coming along as I learn how to be more interesting to her. She’s innately more independent than he is. Because Solo is smart, he learned how to, ignore me. Coda is already more methodical. She’s a puppy perfectionist. Once she gets into scent, she slows down to a crawl and works out the problem at a pace that I find both frustrating and admirable. She wants to get her nose on the training aid and anything short of that isn’t good enough. But it isn’t always possible to do that. She’s also an agile little gymnast. I didn’t train Solo for disaster work, but I think Coda might excel because of her love for scrambling and balancing. Of course, that means I will need to step up my game and learn a whole new demanding set of skills. But Solo in retrospect was so easy to train that I look back and sigh in nostalgia.

Do you have plans to write another book? What’s next for you, Coda, and Solo?

Of course I have plans to write another book. I learned so much writing this one. I’m still narrowing down the topic. The next step for Coda? I hope to certify her in the near future. Solo, I’m sad to say, is retired. I shed some tears, but it was time. We had so much fun while it lasted. He’s still healthy and happy despite his age. He joins Coda and me in training sometimes and still shows Coda what it means to be passionate and focused in your work. She’s competitive, so she goes nuts waiting in the car, watching him work. And he is still so incredibly efficient. I love watching him solve problems. By the time I let Coda out to work, she doesn’t saunter. She flies. Solo is teaching her, just as he taught me.

About The Author

Photograph by Juli Leonard

Cat Warren is a professor at North Carolina State University, where she teaches science journalism, editing, and creative nonfiction courses. Before starting her academic career, Warren worked for newspapers across the United States, reporting on crime, poverty, and politics, from California to Wyoming to Connecticut. Warren started training her young German shepherd, Solo, as a cadaver dog in 2004. She and Solo were called to search for the missing across North Carolina for a number of years. She lives in downtown Durham, North Carolina, with her husband, David Auerbach, a retired professor of philosophy at North Carolina State University, and their two German shepherds. Visit

Product Details

  • Publisher: Touchstone (March 10, 2015)
  • Length: 368 pages
  • ISBN13: 9781451667325

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Raves and Reviews

"What the Dog Knows is a fascinating, deeply reported journey into scent, death, forensics and the amazing things dogs can do with their noses: sniffing out graves, truffles, bedbugs, maybe even cancer. But it's also a moving story of how one woman transformed her troubled dog into a loving companion and an asset to society, all while stumbling on the beauty of life in their searches for death."

– Rebecca Skloot, New York Times Book Review

"A former journalist, the author possesses a keen sense of detail and pacing that informs, entertains, and quickly draws readers into her life and work with Solo."

– Library Journal

“Warren writes . . . with the research-forward focus of an academic and the sweat-and-scabs storytelling of someone who has lived in the field. What the Dog Knows is an incredibly poignant book about dogs and people and how the lost can become found again.”

– Indy Week

“Warren writes with verve and provides rare insight into our working partnership with canines.”

– Kirkus Reviews

What the Dog Knows has so much to offer to handlers, trainers, and dog people in general. A full reporting of the stories here would rob you of the roller-coaster of emotions that Cat and Solo experience, and I want you to experience them for yourself. Warren is obviously a very skilled and entertaining writer, while never writing down to anyone from a high post. You will truly like Cat Warren as she reveals herself in the book, and you’ll feel her pride in her partner ‘Solo.’”

– German Shepherd Adventures

“A meaty, fascinating tour of not only what led humans to train dogs to sniff drugs, bombs and dead bodies, but also the science behind why dogs can be good at these tasks.”

– Raleigh News & Observer

“The author doesn't just talk about her experience. She explains the training and science labs. She explains what other trainers and handlers do. The reader will read about animal psychologists, forensic anthropologists, breeders and scent researchers. It's all explained in an easy-to-read yet detailed narrative. This is a fascinating book for dog lovers and for those who want to know more about how dogs help us each and every day.”


“Warren highlights the profound partnership developed between humans and dogs during their intense, but positive training, and in real situations. We are with her as she starts training her dog, and throughout the mistakes, triumphs, struggles, and rewards. I was entertained and educated—much of what I learned about dogs I had never encountered in any other book. …The people and dogs who inhabit this world are unforgettable.”

– Stacey O'Brien, author of Wesley the Owl

“Working dogs, be they search and rescue, cadaver or explosive detection specialists, are—like their human partners—a breed apart. They inhabit a world of complete commitment, utter dedication, and extraordinarily rigorous training. What the Dog Knows is greatly enriched by author Cat Warren’s own love of digging. She and Solo take us on some fascinating detours through history and phony-baloney claims en route to the science, wonder and awe that all rightly surround dogs’ noses.”

– Sue Russell, author of Lethal Intent and The Illustrated Courtroom

What the Dog Knows is first the story of the relationship between a hard-working cadaver dog and his human companion. But that deeply felt relationship opens the way to an exploration of the working dog world and in doing so becomes something more—a realization of the intelligence, determination, and decency of these animals, a story both wonderful and wise.”

– Deborah Blum, author of Love at Goon Park and The Poisoner’s Handbook

“In a series of accounts that sometimes read like detective stories, Cat Warren … takes us through the steps needed to create dogs that search for people—both living and dead—while describing her life and her special bond with a German shepherd named Solo.”

– Stanley Coren, author of Born to Bark and Do Dogs Dream?

“The capabilities of these specially trained working dogs are remarkable. The author provides fascinating insider information about a meaningful partnership that has important legal and personal consequences.”

– Amy Hempel, author of Reasons to Live and The Dog of the Marriage

“Cat Warren has captured both the magic and the best science behind the success of the modern working dog. This book masterfully shows how even the best technology cannot compete with our best friends. If you have ever wondered what dogs are truly capable of this is the book for you.”

– Brian Hare, evolutionary anthropologist and author of The Genius of Dogs

“It doesn't take a dog-lover (such as myself) to appreciate Cat Warren's remarkable What the Dog Knows. Prepare to be enthralled and enlightened by this story of Solo and his mistress whose clear, lively, personal and intelligent writing will nail you from page one. It's a toss-up as to who is more fascinating--the dog people or the dogs themselves--in this wonderful and altogether unique book.”

– Lee Smith, author of The Last Girls

What the Dog Knows is a fascinating exploration into the minds and characters of some very special dogs. No one who cares about dogs should miss this smart, funny, and at times surprisingly moving book.”

– Spencer Quinn, author of Dog on It

“Enter the fascinating world of working dogs.”

– Temple Grandin, author of Animals in Translation and Animals Make Us Human

“A beautifully written, fascinating, heartwarming, and oft-hilarious homage to working dogs. A must-read for anyone who wants to know more about four-legged working heroes. I'd like to shake Solo's paw for inspiring Cat Warren to write it.”

– Maria Goodavage, author of Soldier Dogs

“Move over CSI, and make way for Cat Warren and her forensic dog Solo to grab and keep your attention. What the Dog Knows is beautifully and compelling written—not only could I not put it down, I didn't want to.”

– Patricia B. McConnell, PhD, CAAB, author of The Other End of the Leash

“Warren’s painstaking research on the history and science of working dogs debunks myths and explains what is known--and how much remains unknown--about canine abilities and behavior. By combining this hard information with anecdotes about training Solo, accounts of searching the North Carolina woods for dead bodies, and the stories of other trainers and their dogs, she has produced a book that is both informative and entertaining. Although her love for Solo is palpable, she remains analytical and clear-headed, never romanticizing what he or other working dogs do.”

– Bruce DeSilva, author of the Mulligan crime novels

“A gifted story-teller, Cat Warren takes us on a fast-paced journey into the scents—some foul, some sweet, some softer than a breeze—of police detective work. This is a book for anyone who loves dogs, and has watched them catch a scent on the wind or in the leaves on the ground, and wondered about that brilliant organ they possess: the nose.”

– Virginia Morell, author of Animal Wise

"Just finished What the Dog Knows, Cat Warren's wonderful new book about the training of her cadaver dog, Solo. This is a real treat for serious dog people: informative, compelling, moving, sad, funny, the works. I loved it."

– Carol Lea Benjamin, author of Dog Smart: The Art of Training Your Dog

“Fantastic … Should be mandatory reading for any police dog handler or trainer.”

– Andrew C. Revering, Chief of Police, Ret., Anoka, Minnesota Police Department

"More than a fascinating, inspiring look into the world of dogs and how dogs learn, What the Dog Knows illuminates--and celebrates!--the special bond we share with dogs. If you have ever loved a dog, you must read this book. I loved it!"

– Robert Crais, author of Suspect

“Delving into the history of working dogs, Warren mixes personal memoir with historical fact to present a fascinating and comprehensive work.”

– Best Friends Magazine

“Warren teaches science journalism at North Carolina State University and has strong investigative and storytelling skills, which makes the book all the more enthralling and engaging. This book offers new avenues to learn about the cognitive and emotional lives of one’s own dogs, and is highly recommended by this reviewer.”

– Bark

“It’s a lively read, rich with details on the exhausting and rewarding process of training a working dog, but in the end, you realize that the process is really about bonding in a way that transcends — or perhaps sidesteps knowing.”

– Natural History

“ 'People are smart, just like dogs.’ Seriously, how do you not like a book that contains that line? . . . Warren was a journalist, is now a professor, and knows her way around a sentence. She clearly cares about the subject and has invested a lot of time and effort into getting to know it, her style is engaging and charming(I was chuckling within a couple of pages), and she doesn’t mind showing her own failings and weaknesses. . . . Fascinating, entertaining, and educational —can’t ask for much more than that.”

– The Irresponsible Reader blog

“A combination of memoir, history, and science that is so very readable that it’s like sitting down for a cup of coffee and a conversation with the author.”

– Cape Cod Times

Awards and Honors

  • Paradies Lagardere Non-Fiction Airlines Pick

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