From prey drive to problem solving to direct odor imprint
Around twenty five years ago, when I began introducing hunting breeds into police detection work, many trainers laughed at the idea. At that time, the Malinois was widely considered the only serious candidate for professional detection work. The reasoning appeared logical. Detection dogs needed enormous motivation, determination, physical power, and the willingness to do almost anything to obtain their reward. A dog that would chase, bite, carry, and fight for a metal pipe was considered ideal.
In many police and military programs, dogs were therefore selected primarily for extreme prey drive. The dog needed to be sufficiently obsessed with a toy, ball, Kong, towel, or metal pipe. The target odor was placed on, inside, or near that object. Trainers then attempted to transfer the value of the object to the odor. The underlying assumption was simple: the stronger the dog’s desire for the object, the stronger the detection performance would eventually become. For a long time, this belief shaped both dog selection and training methodology. When I started working with Labradors, spaniels, Nova Scotia Duck Tolling Retrievers, and German Wirehaired Pointers, many experienced trainers told me these breeds would never become serious operational detection dogs. They were considered too soft, insufficiently intense, too sensitive, or simply unsuitable for demanding police work. I saw the problem differently.
For me, the central question was never how desperately the dog wanted a toy. The real question was whether the dog could recognise, locate, discriminate, and communicate the presence of a target odor with accuracy, confidence, and independence. These are not the same abilities. A dog can possess extraordinary prey drive and still be impulsive, inaccurate, environmentally unstable, overly dependent on the handler, or unable to regulate its arousal. A dog can fight intensely for a reward without necessarily being a careful and systematic odor problem solver. Likewise, a dog that appears less spectacular during a traditional toy test may possess excellent olfactory search behaviour, persistence, environmental stability, independence, concentration, and cognitive flexibility. The detection world has often confused visible intensity with functional ability.
The dog that wants the reward
Strong motivation is important in detection work. We cannot simply remove it from the equation. Explosives, narcotics, human remains, electronic devices, and most other operational targets have no natural biological significance for the dog. The target odor does not automatically provide food, safety, reproduction, play, or social contact. We must create its significance through learning.
Lucia Lazarowski and her colleagues at Auburn University describe reward value as an essential component of explosives detection training. Because explosive odors have no intrinsic value to dogs, trainers need a strong relationship between detecting the odor and gaining access to a meaningful reinforcer. However, motivation should not be treated as a single quality that can simply be measured as high or low. Lazarowski has noted that terms such as play drive, prey drive, food drive, hunting drive, and work drive are often grouped together under the vague label of drive. This creates a problem.
When trainers say that a dog has enormous drive, what exactly do they mean? Does the dog search persistently? Does it remain concentrated when the target is difficult to locate? Does it continue working when reinforcement is delayed? Can it regulate frustration? Can it disengage from distractions?Can it work independently without ignoring relevant information from the handler? Can it recover after making an error? Or does the dog simply become highly aroused when it sees a ball? These are very different behavioural characteristics. Motivation can support learning, endurance, and persistence. Excessive arousal, however, can also reduce behavioural precision. It may cause the dog to move too quickly, skip search areas, respond impulsively, or become focused on obtaining the reward rather than solving the odor problem.
Interestingly, Lazarowski’s 2025 study on marker training found that dogs with higher reward motivation took longer to learn the initial sit behaviour. The researchers suggested that high reward motivation may have increased arousal and temporarily interfered with learning. They also made clear that motivation may have different effects depending on the nature of the task. In another detection task, higher reward motivation was associated with faster acquisition. This is an important nuance.
High motivation is not automatically good or bad.
Its value depends on the task, the dog, the training system, and the level of behavioural control required. The most motivated dog is therefore not automatically the best detection dog. The best dog is the dog whose motivation can be transformed into accurate, stable, and functional search behaviour.
Selection must be mission specific
One of the most important messages in Lazarowski’s work is that detection dog selection should be based on the actual operational task. There is no universal detection dog. A dog searching luggage at an airport requires a different balance of characteristics than a dog searching open terrain. A dog screening moving people for explosives needs different natural search tendencies from a dog examining vehicles, buildings, parcels, or buried sources. A military dog working in a combat environment may need different environmental and behavioural characteristics from a conservation dog searching for animal scat or a medical detection dog working in a controlled laboratory. Lazarowski and her colleagues divide important explosives detection characteristics into three broad areas.
The first is detection behaviour. This includes odor guided searching, hunting tendencies, search style, sniffing behaviour, and the dog’s natural inclination to investigate odor.
The second is trainability and tractability. This includes learning ability, motivation, sociability, cooperation, independence, and the capacity to respond appropriately to training.
The third is environmental soundness. This includes the ability to work reliably around crowds, noise, vehicles, unfamiliar surfaces, buildings, transport systems, and other operational pressures.
This model is far more useful than asking whether a dog has enough prey drive. It also helps explain why hunting breeds can perform exceptionally well in detection work. Many hunting breeds were selectively bred over generations to use odor, search large areas, maintain persistence, cooperate with people, and continue working under changing environmental conditions.
That does not mean every Labrador, spaniel, or pointer will become a good detection dog. It also does not mean that a Malinois cannot become an exceptional detection dog. Breed is not the complete answer. The individual dog and the operational role must be matched carefully. The traditional Malinois was often selected for a combination of patrol work, apprehension, protection, obedience, physical strength, and detection. In dual purpose police and military systems, this versatility can be extremely valuable.
However, some of the characteristics that support protection or apprehension work may not always be ideal for highly specialised detection tasks. Lazarowski’s review notes that certain specialised explosives detection roles, such as screening people, may be less compatible with behavioural tendencies required for other duties.This is not criticism of the Malinois. It is recognition that selection must be based on function. The question should not be: Which breed is the best? The question should be: Which dog possesses the best combination of characteristics for this specific task?
Persistence is not enough
Traditional selection frequently rewarded the dog that refused to give up. Trainers wanted to see persistence. They wanted the dog that continued chasing, searching, biting, or retrieving despite physical obstruction, frustration, or repeated failure. Persistence is certainly valuable, but Lazarowski’s research shows why it should not be considered in isolation. In one study, 81 candidate detection dogs were given an unsolvable task. The dogs could see or smell a desirable reward but could not access it. Researchers measured both task persistence and human directed behaviour. Persistence was high across the dogs, but it did not predict which dogs would later succeed in detection work.
Human directed gazing at eleven months of age, however, was associated with successful placement as a detection dog. The successful dogs were not merely persistent. They had also developed the ability to gather information from a person when confronted with a problem. This finding challenges a common idea in working dog culture. Independence does not mean that a dog should completely ignore the handler. Cooperation does not mean that a dog should constantly seek help. The professional detection dog requires a functional balance. The dog must search independently enough to avoid becoming dependent on handler cues. At the same time, it must remain part of a cooperative team.
A dog that blindly persists with the wrong strategy is not necessarily demonstrating intelligence or operational resilience. It may simply be repeating unsuccessful behaviour. Effective problem solving includes persistence, but it also involves flexibility. The dog must be capable of adjusting its behaviour when the current strategy does not produce success. This is particularly important in complex detection work. Odor behaves dynamically. Airflow changes. Sources may be inaccessible. Residual odor may remain after the source has moved. Contamination may produce complex odor pictures. Multiple odor plumes may overlap. The dog must do more than run fast and search hard. It must process information.
From kong imprinting to Direct Odor Imprint (DOI)
My own concerns about traditional training methods eventually led me to develop Direct Odor Imprint, or DOI. Traditional detection training often began by creating intense value for an object such as a Kong, ball, towel, PVC pipe, or metal tube. The target odor was then paired with that object. Sometimes the object was impregnated with the target odor. In other systems, the target material and the reward were placed together. The intention was to make the dog transfer its desire for the object to the target odor. This can work. Thousands of detection dogs have been trained through some form of odor and reward pairing. The fact that a method can produce working dogs, however, does not mean that it is always the clearest or most efficient learning process. My concern was that the dog might not learn exactly what the trainer believed it was learning.
When several stimuli are presented together, they can compete for predictive value. A highly salient object may overshadow a less obvious odor. The dog may learn the smell of the Kong, rubber compounds, saliva, metal, adhesive, human handling, packaging material, or a combination of these cues. The trainer may think that the dog is learning the target odor while the dog is actually learning a much broader and less controlled odor picture.
Blocking may also become relevant when an already established predictor interferes with learning about a new one. When the dog already understands that the Kong or toy predicts reinforcement, adding a target odor does not guarantee that the target odor will acquire equal behavioural significance. Proofing can reduce some of these unwanted associations, but proofing is often used to repair a problem that was created during the original learning process.
DOI begins from a different principle.
Train the dog directly on the information that ultimately matters. The target odor itself should predict the opportunity to earn reinforcement. The toy or food remains the primary reinforcer, but it is delivered as a consequence of the dog’s correct response to odor. It does not need to be hidden with the odor or physically attached to the source. This creates a cleaner contingency. Target odor leads to the correct behaviour. The correct behaviour produces a bridge signal. The bridge signal predicts reinforcement. There is no need to make the dog believe that the target odor is a Kong. The dog only needs to learn that locating and communicating the target odor gives access to something it values.
Marker training and clear communication
Lazarowski’s recent work on marker training supports important elements of this approach. In a controlled study involving 28 candidate detection dogs, half of the dogs were trained with a clicker as a marker and half received the reward without a marker. The marker trained dogs completed training in fewer trials. They performed the trained alert more accurately, indicated the location of the source more precisely in operational searches, and showed greater resistance to extinction when the primary reward was temporarily withheld. The important element is not the mechanical clicker itself. The clicker is simply one possible bridge signal. A whistle, tone, spoken word, or another clear signal can perform a comparable function when conditioned and applied correctly. Lazarowski and her colleagues explicitly state that the findings are likely relevant to different marker types. 
The marker solves a timing problem.
The dog may locate the odor several metres away from the handler. Reinforcement cannot always be delivered at the precise moment of the correct response. By the time the handler reaches the dog or produces a ball, the dog may have moved, looked away, scratched, sat incorrectly, or offered another behaviour. The bridge identifies the exact moment at which the dog met the criterion. It tells the dog: that decision was correct, and reinforcement is coming. The study also describes several potential advantages for detection training. A marker can create a clearer relationship between odor and reward without placing the reward at the odor source. It can reduce contamination and confusion. It can improve the precision of the trained final response. It can support work at a distance and reduce handler dependence. This aligns closely with the logic of DOI. The primary reinforcer does not need to be presented with the odor for learning to occur. What matters is a clear, accurately timed contingency between the dog’s response to odor and access to reinforcement.
The problem solver
Today, hunting breeds are increasingly visible in police, military, conservation, medical, and specialist detection programs. Labradors, spaniels, pointers, and crosses between hunting breeds are no longer considered unusual choices. This does not mean the detection world should simply replace one breed prejudice with another. The lesson is not that hunting dogs are good and Malinois are bad. The lesson is that selection based almost entirely on extreme prey drive is too limited for modern detection work.
A professional detection dog must be motivated, but also accurate.
It must be persistent, but also adaptable. It must work independently, but remain cooperative. It must be energetic, but capable of regulating arousal. It must search quickly when speed is required, but carefully when the target demands detailed examination. It must tolerate frustration without becoming chaotic. It must possess the confidence to make decisions without constantly waiting for information from the handler. As I work on my new book today, my working cocker spaniel regularly approaches me carrying a metal Odor Delivery Device in her mouth. It is her unmistakable way of telling me that she is ready to work. There is something wonderfully ironic about that image.
Twenty five years ago, many trainers believed that hunting dogs would never become serious operational detection dogs because they lacked the necessary intensity. Today, my spaniel carries the same kind of metal device that once symbolised the traditional prey driven selection system. But she does not carry it because it was impregnated with target odor or because she was trained to believe that metal itself is the objective. She carries it because it has become part of a training game she understands and enjoys. The equipment signals an opportunity to solve an odor problem. That is an important difference.
For many years, the detection world selected dogs according to how desperately they wanted the reward. Modern research is encouraging us to look more carefully at the complete dog. Motivation remains essential, but it must be considered together with cognition, emotional stability, environmental soundness, search behaviour, cooperation, independence, and the specific demands of the operational task. Perhaps we have spent too much time asking how badly the dog wants the Kong or the ball. The more important question is how well the dog can solve the odor problem.
