Scent Detection Terms in Scent Detection

Air Scenting – A technique a dog may use to locate target odor where he searches wind or air currents

Ageing – The amount of time between placing a hide and when dogs begin searching. During this time odor disperses into the surrounding air, generally making it easier to find. Generally, try to age for at least 5 minutes. Train for short and long ageing so your dog is accustomed to different scent profiles.

Aggressive Alert – When a dog scratches, bites, or disturbs hot objects in a way that may contaminate the search environment. Aggressive alerts may be penalized or failed, depending on the discipline and organization.

Alert – The predetermined response the dog offers when he has located target odors. The handler says alert (and may raise his arm) while his dog is indicating source to let the judge know he has found the location

Altered aka fixed aka spayed or neutered – The technical term for a dog of either gender which has been surgically made unable to reproduced

American Kennel Club (AKC) – a purebred dog registry based in USA, which offers competitions in canine scent work

Benching/ Benching area – To set up one’s belongings, dog crate, etc. in a designated area at a competition while the handler waits between turns competing

Blind – A type of search where the handler doesn’t know the location of the target odor, since it was hidden by somebody else

Blocking – When a handler is standing in the dog’s way and prevents the dog from searching or moving to that position. For example, if a handler is standing on top of a hide, he is blocking his dog.

Bracketing – The dog moves left and right, back and forth, searching for scent

Breed Standard – The blueprint for the ideal specimen f a purebred dog of a certain breed, including functions for which it was bred, appearance, temperament, size, colors, etc. Breed standards may vary between countries and between registering bodies e.g. United Kennel Club vs Canadian Kennel Club, Federation Cynologique Inernationale, etc.

Canadian Kennel Club (CKC) – The primary registering body for purebred dog breeds in Canada, which compiles breed standards, organises events, specifies rules, governs judges, etc.

Change of Behavior (COB)- When a scent detection dog encounters the scent plume, he demonstrates changes of behavior including changes in body posture, speed or direction, ear position, hackle position, tail position or movement, abrupt head turn, breathing change, sniffing change, or any number of other possibilities. Note: The precise definition has diverse meanings to different people. COB is also known as hit, interest, body language, positive response, indicate, behavioural response, changes in dog behaviour, final response, indication, and alert. (See Resources at the bottom for references).

Classical conditioning (aka Associative Learning, Pavlovian conditioning) – When an animal learns to associate two things that go together e.g. when a dog’s repeatedly hears a metronome and then food is presented to him, he forms an association between the metronome and food. He “reacts to the signal in the same way as if it were food: no distinction can be observed between the effects produced on the animal by the sounds of the beating metronome and showing it real food” (Pavlov, 1927, p. 22). Note that salivation in response to the metronome or food is an involuntary response. Another example is when a trained hunting dog hears the sound of gunfire, he associates that sound with birds, and upon hearing the gunfire he demonstrates excited behaviors such as lifting his head, eyes widening and increased heart rate, in anticipation of the birds to follow.

Clear – An area that is free of target odor. (When a handler determines that their dog has finished searching an area and no target odor is present, they may say “clear” to communicate that decision to event officials.)

Clever Hans – Clever Hans was a horse who became famous for doing math, and counting by tapping his hoof (1). Researchers eventually realized that Clever Hans was simply a master at reading the body language of the people posing the questions. Without their assistance, he couldn’t perform the feats that made him a star. But, even knowing this, researchers were unable to control their body language sufficiently to prevent the horse from reading them. Learn more at:

Cocktail – A combination of more than one target odor. For example, in Sniff Alberta (UKC Nosework), we usually search for a combination of Birch, Clove, Anise and Wintergreen target odors. To prepare a cocktail, a drop of each odor should be placed in a separate location on a piece of blotting paper, rather than combining them into a soup which may have unpredictable chemical reactions.

Cold – Objects that are free of odor are called “cold” (vs. objects that contain target odor are called “hot”).

Contaminated a) If the handler drops food in the search area, he is faulted for contaminating the area. b) When scent is mistakenly taken from where it should be in a clearly marked container to an area that should be free of it. As a result, handlers may be confused when dogs don’t search or react as expected.

Correction – Punishing a dog e.g. using a leash pop or jerk, shouting, which may be faulted by the judge as unsporting behaviour, or dismissed if the treatment of the dog is overly harsh.

CWAGS (Canine Work and Games) – An organisation that offers titles in scent, obedience, rally obedience and games

Commitment to Odor aka Odor Commitment – When the dog has value for odor, forms a positive association, and odor becomes rewarding

Cues – Words, gestures or things in the environment that a dog may be trained to respond to with specific behaviors. For example, scent dogs respond to cues to search by searching for a specific scent, including: when their handler says “find it”, taps an object, sweeps his hand near an object, attaches a specific leash to a harness, or approaches boxes in a scent detection lab

Dismissed – Asked by a judge or official to leave a search or competition e.g. if a dog bites a spectator during a trial

Distraction aka non-target stimulus– An intentionally distracting toy or food (odor) is required to be included in superior+ level UKC nosework searches e.g. tennis ball or peanut butter placed inside a box in Master Container Searches

Double-Blind Searches – In double blind searches, an experienced person places hides and leaves until the test is completed, to prevent (intentionally or unintentionally) communicating its position to the team during the search. (Usually the number and placement of hides is determined by rolling dice.) A proctor is present during the test to ensure teams don’t break the rules (such as having the handler find hides by visual inspection). The proctor has no knowledge about the hides and has no vested interest in the outcome. The scent detection handler does not know how many hides are present or where they are. The handler receives no feedback about whether they are right or wrong until the results are recorded. Once all of the results are compiled, the person who places the hides determines whether teams passed or failed. (See also

Elements – In UKC nosework competition, there are 4 Elements, types of events according to the search environment:

  1. Pre-trial– Inside a box. The dog searches a row of boxes and demonstrates that it recognizes the target odor. This is the easiest type of search. This is the first step which must be passed in order for dogs to compete in the other elements.
  2. Container– Inside a box. The dog searches a row of boxes. To increase the difficulty, more boxes, different shapes and distractions may be added.
  3. Interior– The hide is secured inside, underneath, between or on top of objects inside a building. For example, the dog may search an office where the hide is taped under a chair.
  4. Vehicle– The hide is secured on the outside of a vehicle, for example, on the front bumper. More advanced searches include more vehicles, and different types of vehicles e.g. buggies, ATVs, or tractors.
  5. Exterior– The hide is secured around an object outside. Surfaces may include grass, gravel, leaves, snow, etc. Because of changing wind and weather conditions, and frequency of animal smells including urine, this is the most difficult type of search.

Elimination – Dog urinates or defecates in the search area resulting in failing that search

Event Listing – A brief description of an upcoming event on the UKC website, describing a nosework trial (including events & levels offered, location, fees, judge, etc.)

False Alert – The handler calls an alert when there is no odor present but the dog has indicated, or when the room has odor present, but the dog indicates in the wrong location

Finish a) Complete all of the requirements for a title b) Once all the hides in a search are found, the handler must say “finish” to stop the clock. If the handler doesn’t say finish, he won’t fail, but he will be faulted.

Focussed response – An indication where the dog freezes and stares at source with intense focus

Formal Indication aka Trained Final Response– Dog is trained to perform a freeze with focused attention, sit or down at the source (highest concentration of target odor)

Fringe – The dog indicates when he is close to the target odor, but not at source. This occurs when the dog has a training deficiency and responds on lower thresholds of odor and does not work odor truly to source. For example, the dog indicates by lying down on the driver side of a vehicle when the hide is actually on the front bumper and wind is blowing scent to the dog’s location. Depending on the situation, fringe alerts should be faulted (but with a passing score) or will result in non-qualification (failure).

Full Nosework Trial – A club includes all 4 elements at the same trial and competitors must compete in all 4 elements at the same level. For example, a Novice Nosework Trial would include Novice Container + Interior + Vehicle + Exterior.

Handler Discrimination – A nosework event where the dog searches for his handler’s scent on a glove in one of the boxes presented in a row.

Handler Error – The handler makes an error when the dog’s performance may have been without fault. For example, the handler may call an alert twice on the same box in a superior level container search.

Head snap – The dog makes an abrupt change of direction when he picks up the scent

Hide – The package of target odor inside a ventilated container that is hidden in the search area for the sniffer dog to find. For example, one common type of hide is made from placing a cotton swab scented with target odor inside a metal tin with magnets, which easily secure the hide to a metal surface e.g. vehicle. Other common hide containers include lip balm containers, envelopes, shipping labels, tubes, etc.

High in Trial – The award given to the team with the fastest faultless search, pulled from all section and levels and events held at a single nosework trial.

High Value Rewards – Spectacular rewards the dog finds highly motivating, even in what might otherwise be a distracting situation. For example, a dog might be very exciting about steak rewards (high value), while he would not always be interested in a piece of lettuce (lower value).

Hot – Objects that contain target odor are called “hot” (vs. objects that are free of odor are called “cold”).

Indication aka Trained Final Response – The behaviour (or chain of behaviors) the dog displays to show that he’s made a decision about the exact location of the source of target odor e.g. freeze like a statue with eyes staring at source

Individual Element Trial – A nosework trial that picks and chooses from the 4 elements available e.g. a club could offer containers and interior elements only

Intact – A dog that is able to reproduce, not spayed or neutered

In season aka Estrus aka in heat – The stage in a female dog’s reproductive cycle during which she becomes receptive to mating with males. Females in season are ineligible to compete in nosework trials.

Judge’s Briefing – The judge shows competitors the search area and explains relevant details such as the start line, any safety concerns, the time available, then recaps applicable rules and/or responds to questions from competitors.

Junior Handler– A participant aged 2-18 years who participates in UKC events under the applicable Junior Rules and Regulations (

K9 ABC Games – A nosework organization created to provide dog/handler teams with a relaxed yet realistic search challenge designed to further the teams’ skills. Although ribbons may be awarded for each earned leg and title, placements are not calculated. See

Kibble – A slang term for dry commercially available dog food (as opposed to moist diets, raw food, etc.)

Lab, Scent Detection – A training lab is an arrangement of boxes and drawers used to control the environment while teaching new dogs how to systematically search for target odor and to indicate (see Andrew Ramsey’s training video), while avoiding undesirable behaviours such as digging. In Hunter’s Heart scent detection lab, the white cardboard boxes have ~3 inch diameter holes in them. The hide container e.g. tin containing scented paper is taped inside the box close to this hole. So we know when the dog’s nose is inserted into the hole, that he is very likely smelling the highest concentration of target odor. This makes our criteria for success very concrete, resulting in more timely, clearer rewards.

Leaving Source – The dog quickly leaves the target odor location

Leg – One passing search towards a nosework title e.g.  a team passes one novice container search. (2 passes are required to complete a title.)

Luring – A handler places a reward in front of the dog’s nose and moves it to elicit a desired behavior. For example, when a handler places a cookie a the dog’s nose and draws him away from an odor

Match – An informal event without strict rules, used to practice and gain experience

Missing Hides – When a dog passes by a trained target odor without finding or alerting on it

Multiple Hides – A search where more than 1 hide is placed in the area. For example, a Superior level UKC container search will include one box with a clove hide and another box with either a birch or anise hide.

Move-up – When a handler has entered and event, but subsequently completes a title, he has the option to continue to compete as entered in the B class, or fill out a move-up form to advance to the next level. For example, a handler completes his novice container title in Trial 1 on Saturday, and completes a move-up form so he can compete in Advanced Containers in Trial 2 on Sunday.

National Association of Canine Scent Work (NACSW) – A scent detection governing body, which offers competitions, trains officials and judges and promotes the sport of nosework.

Nosework – A sport whereby pet dogs search for designated target odors, usually essential oils such as Birch, Anise, Clove

Novel Effect – When a scent dog alerts on a new scent that has not been trained. For example, a dog trained to find birch alerts on wintergreen. This may sometimes be due to chemical similarities between the novel odor to trained target odor

Odor (aka scent) – volatile emanation from any substance that stimulates the olfactory receptor cells aka scent (

Odorant – chemical particles that trigger the sense of smell

Olfaction – the sense of smell, the ability to perceive and distinguish odors (Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. (2003). Retrieved November 15 2017 from

Operant Conditioning (aka instrumental conditioning) – A learning process whereby the strength of a behavior is modified by rewards and/or punishments. For example, when a dog sits, it receives a cheese reward (aka positive reinforcement). This increases the likelihood that it will sit again in future. Note that the behavior (sitting) involves a choice by the animal, in order for the consequence to occur (cheese).

Paired, Pairing – When food is located with the target odor, so that dog can self-reward immediately when he arrives at source, without the interference of the handler

Pheromones – Ectohormones secreted by one individual and detected by a second individual of the same species, which produces a change in its sexual or social behavior (

Punishment – Something that causes a behavior to be less likely. For example, when a dog tries to steal a turkey off the dinner table, the owner yells “no”

Relationship Building – Doing something with your dog that you both enjoy. Over a period of time, the strength of the bond between the handler and dog increases. Typical results include increased attention, enthusiasm, and fun.

Rewards – Something that causes a behavior to be more likely. For example, when a dog sits, it receives a cheese reward (aka positive reinforcement). Rewards are things the dog likes, such as food, toys, life rewards (running in the field), verbal praise, touch, etc.

Reward placement – the physical location where the reward is delivered. For example, when a dog’s nose touches a hide, the handler delivers the reward at that location. While the dog is enjoying his reward, he is continuing to smell the target odor. Because rewards appear at source, the dogs learn to focus their attention at source, clearly communicating where it is, which is very helpful during blind searches.

Scent detection  – An activity whereby an animal (or machine) perceives/detects a specific scent (aka target odor) e.g. an elephant can be trained to detect the scent of explosives and indicate the location of a landmine by raising its forelimb.

Smell – the sense that provides information about an object’s scent, often giving clues to the palatability of food, the safety of air, etc. The organs of smell, in humans, include patches of olfactory membranes each about the size of a postage stamp, located just under the bridge of the nose (

Sniff Alberta – A canine nosework club in Alberta, Canada

Sniffing Dog Sports (SDS) – An organization that offers canine nosework

Sporting Detection Dogs Association (SDDA) – An organization that offers canine nosework

Source – The precise location of highest concentration of target odor. For example, if the dog is searching a vehicle where odor is hidden behind the license plate, the source is the exact position on the license plate where it is located, within 2-6 inches e.g. behind the red year sticker. While the dog is actively searching around the license plate, he is close to the source, but not “at source“. The handler must wait until the dog indicates to know the exact location. Once the dog indicates, the handler calls out “alert”, to let the judge know the dog has found the source.

Sourcing – After encountering the scent plume, the dog searches for the precise location of “source” (the highest concentration of target odor).

Target Odor – A specific scent the dog is trained to recognize e.g. Betula Lenta essential oil for nosework competition, the scent of decomposing human remains for cadaver dogs

Trained Final Response – When a scent dog shows that he has found target odor with a consistent behavior such as sitting, lying down, freezing like a statue, barking, digging, etc.

United Kennel Club (UKC) – A large, international kennel club which offers canine nosework competitions


For more detailed scent detection terminology, see also:

  1. Canine Olfaction Science and Law, Advances in Forensic Science, Medicine, Conservation, and Environmental Remediation, Ed. T. Jezierski et al, Taylor & Francis Group, Boca Raton, USA, 2016.
  2. UKC Nosework Rules 2015, Chapter 16 Definitions, page 32 at:
  3. Search and Rescue – VSRDA Glossary at:

For a detailed description of canine learning, see Pamela Reid’s Excel-erated Learning, Explaining How Dogs Learn and How Best to Teach Them, James and Kenneth Publishers, Berkeley, USA, 1996.

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