A detection dog or sniffer dog is a
dog
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...
that is trained to use its
sense
A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of Stimulus (physiology), stimuli. (For example, in the human body, the brain which is part of the cen ...
s to detect substances such as
explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...
s,
illegal drug
The prohibition of drugs through sumptuary law, sumptuary legislation or religious law is a common means of attempting to prevent the Recreational drug use, recreational use of certain intoxicating substances.
While some drugs are illegal to p ...
s, wildlife scat, currency,
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...
, and
contraband
Contraband (from Medieval French ''contrebande'' "smuggling") refers to any item that, relating to its nature, is illegal to be possessed or sold. It is used for goods that by their nature are considered too dangerous or offensive in the eyes o ...
electronics such as illicit mobile phones. The sense most used by detection dogs is
smell. Hunting dog
A hunting dog is a canine that hunts with or for hunters. There are several different types of hunting dog developed for various tasks and purposes. The major categories of hunting dog include hounds, terriers, dachshunds, cur type dogs, and g ...
s that search for
game
A game is a structured form of play (activity), play, usually undertaken for enjoyment, entertainment or fun, and sometimes used as an educational tool. Many games are also considered to be work (such as professional players of spectator s ...
, and
search dog
A search-and-rescue dog is one trained to find missing people after a natural or man-made disaster. The dogs detect human scent and have been known to find people under water, under snow, and under collapsed buildings.
Applications
A dog w ...
s that work to find missing humans are generally not considered detection dogs. There is some overlap, as in the case of
cadaver dog
A search-and-rescue dog is one trained to find missing people after a natural or man-made disaster. The dogs detect human scent and have been known to find people under water, under snow, and under collapsed buildings.
Applications
A dog w ...
s, trained to search for human remains.
A
police dog is essentially a detection dog that is used as a resource for police in specific scenarios such as conducting drug raids, finding missing criminals, and locating stashed currency. Frequently, detection dogs are thought to be used for law enforcement purposes. Experts say that dog-sniff evidence should not be used in the criminal justice system, pointing to wrongful convictions, human biases that skew animal behavior, and the lack of systematic research into what dogs detect or how they do it.
Although detection dogs are often used for law enforcement purposes, they are also used as a valuable research tool for wildlife biologists. In
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, detection dogs are trained to discover
quagga mussel
The quagga mussel (''Dreissena rostriformis'', also known as ''Dreissena bugensis'' or ''Dreissena rostriformis bugensis'') is a species (or subspecies) of freshwater mussel, an aquatic bivalve mollusk in the family Dreissenidae. It has an aver ...
s on boats at public boat ramps because they are a harmful
invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
for the environment. Detection dogs also tend to be employed for the purposes of finding and collecting the
feces
Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...
of a diverse array of species, including
caribou
Reindeer (in North American English, known as caribou if wild and ''reindeer'' if domesticated) are deer in the genus ''Rangifer''. For the last few decades, reindeer were assigned to one species, ''Rangifer tarandus'', with about 10 subspe ...
,
black-footed ferret
The black-footed ferret (''Mustela nigripes''), also known as the American polecatHeptner, V. G. (Vladimir Georgievich); Nasimovich, A. A; Bannikov, Andrei Grigorovich; Hoffmann, Robert S. (2001)''Mammals of the Soviet Union''Volume: v. 2, pt. 1 ...
,
killer whale
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus ''Orcinus'' and is recognizable by its black-and-white pa ...
,
and
Oregon spotted frog
The Oregon spotted frog (''Rana pretiosa'', meaning "precious frog") is a member of the frog family Ranidae of order Anura. It is a medium-sized aquatic frog endemic to the Pacific Northwest and historically well distributed in the Puget Trough/ ...
. This process is known as wildlife scat detection.
Detection dogs are also seeing use in the medical industry, as studies have revealed that canines are able to detect specific odours associated with numerous medical conditions, such as
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
.
Functions
Detection dogs have been trained to search for many things, both animate and inanimate, including:
*
Human remains Human remains may refer to:
A corpse or skeleton
* A deceased human body
** A cadaver
** A Human skeleton, skeleton
Music
* Human Remains (band), an American grindcore band
* Human Remains (Hell album), ''Human Remains'' (Hell album), 2011
* Huma ...
*
Bed bug
Bed bugs are insects from the genus ''Cimex'' that feed on blood, usually at night. Their bites can result in a number of health impacts including skin rashes, psychological effects, and allergic symptoms. Bed bug bites may lead to skin changes ...
s
*
Cancer detection
*
Drug
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insuffla ...
s
*
Endangered animal species (e.g.,
black-footed ferret
The black-footed ferret (''Mustela nigripes''), also known as the American polecatHeptner, V. G. (Vladimir Georgievich); Nasimovich, A. A; Bannikov, Andrei Grigorovich; Hoffmann, Robert S. (2001)''Mammals of the Soviet Union''Volume: v. 2, pt. 1 ...
)
![Knapweed Nightmare noxious weed detection dog wearing GPS tracking harness](https://upload.wikimedia.org/wikipedia/commons/f/f3/Knapweed_Nightmare_noxious_weed_detection_dog_wearing_GPS_tracking_harness.jpg)
*
Explosives
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...
*
Fire accelerant
In fire protection, an accelerant is any substance or mixture that accelerates or speeds the development and escalation of fire. Accelerants are often used to commit arson, and some accelerants may cause an explosion. Some fire investigators use t ...
s (e.g.,
arson
Arson is the crime of willfully and deliberately setting fire to or charring property. Although the act of arson typically involves buildings, the term can also refer to the intentional burning of other things, such as motor vehicles, wat ...
investigation)
*
Firearm
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions).
The first firearms originated in 10th-century China, when bamboo tubes ...
s
*
Invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
(e.g.,
quagga mussel
The quagga mussel (''Dreissena rostriformis'', also known as ''Dreissena bugensis'' or ''Dreissena rostriformis bugensis'') is a species (or subspecies) of freshwater mussel, an aquatic bivalve mollusk in the family Dreissenidae. It has an aver ...
)
*
Ivory
Ivory is a hard, white material from the tusks (traditionally from elephants) and teeth of animals, that consists mainly of dentine, one of the physical structures of teeth and tusks. The chemical structure of the teeth and tusks of mammals is ...
*
Currency
A currency, "in circulation", from la, currens, -entis, literally meaning "running" or "traversing" is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes and coins.
A more general def ...
(e.g. large amounts of money carried by passengers in airports that should be declared to
customs
Customs is an authority or agency in a country responsible for collecting tariffs and for controlling the flow of goods, including animals, transports, personal effects, and hazardous items, into and out of a country. Traditionally, customs ...
)
*
Mobile phone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link whil ...
s (e.g. as
contraband
Contraband (from Medieval French ''contrebande'' "smuggling") refers to any item that, relating to its nature, is illegal to be possessed or sold. It is used for goods that by their nature are considered too dangerous or offensive in the eyes o ...
in prisons)
*
USB drives
*
SIM cards
A typical SIM card (mini-SIM with micro-SIM cutout)
A GSM mobile phone
file:Simkarte NFC SecureElement.jpg, T-Mobile nano-SIM card with NFC capabilities in the SIM tray of an iPhone 6s
file:Tf sim both sides.png, A TracFone Wireless SIM card ha ...
*
Mold
A mold () or mould () is one of the structures certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal seco ...
* Plants, animals,
produce
Produce is a generalized term for many farm-produced crops, including fruits and vegetables (grains, oats, etc. are also sometimes considered ''produce''). More specifically, the term ''produce'' often implies that the products are fresh and g ...
, and agricultural items that have to go through customs
*
Termite
Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...
s
*
Wildlife
Wildlife refers to domestication, undomesticated animal species (biology), species, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introduced by humans. Wildlife was also synonymous ...
scat
* Gourmet Fungi, such as
Truffles
A truffle is the fruiting body of a subterranean ascomycete fungus, predominantly one of the many species of the genus ''Tuber''. In addition to ''Tuber'', many other genera of fungi are classified as truffles including ''Geopora'', ''Peziza ...
(e.g. French Black Truffles (Tuber melanosporum), Italian White Truffles (Tuber magnatum pico), Chanterelles (Cantharellus cibarius), "Porcini" (Boletus edulis), Morels (Morchella esculenta), and other varieties of mushroom that, when parasitized by Hypomyces Lactifluorum, are known as a "Lobster mushroom")
Sniffer dogs can be trained to locate small infestations of invasive and non-native weeds. World's first
Spotted Knapweed
''Centaurea stoebe'', the spotted knapweed or panicled knapweed, is a species of ''Centaurea'' native to eastern Europe, although it has spread to North America, where it is considered an invasive species. It forms a tumbleweed, helping to increa ...
K-9 detection program successfully completed field-testing for
Montana State University
Montana State University (MSU) is a Public university, public land-grant university, land-grant research university in Bozeman, Montana. It is the state's largest university. MSU offers baccalaureate degrees in 60 fields, master's degrees in 6 ...
in 2004. Upon completion of the testing,
Knapweed Nightmare
Knapweed Nightmare was the first dog trained "to locate a plant within a plant community" which enabled her to track down low densities of invasive non-native noxious weeds.
Nightmare is a sable German Shepherd, shepherd dog trained by Montana ...
was finding low densities of non-native invasive knapweed rosettes in the field with a 93% overall success rate.
She followed it up with 98% in the final trials in open fields, demonstrating that dogs can effectively detect low densities of invasive plants.
Detection dogs are able to discern individual scents even when the scents are combined or masked by other odors. In 2002, a detection dog foiled a woman's attempt to smuggle marijuana into an Australian prison in
Brisbane
Brisbane ( ) is the capital and most populous city of the states and territories of Australia, Australian state of Queensland, and the list of cities in Australia by population, third-most populous city in Australia and Oceania, with a populati ...
. The marijuana had been inserted into a balloon, which was smeared with
coffee
Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulant, stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world.
S ...
,
pepper
Pepper or peppers may refer to:
Food and spice
* Piperaceae or the pepper family, a large family of flowering plant
** Black pepper
* ''Capsicum'' or pepper, a genus of flowering plants in the nightshade family Solanaceae
** Bell pepper
** Chili ...
, and
petroleum jelly
Petroleum jelly, petrolatum, white petrolatum, soft paraffin, or multi-hydrocarbon, CAS number 8009-03-8, is a semi-solid mixture of hydrocarbons (with carbon numbers mainly higher than 25), originally promoted as a topical ointment for its h ...
and then placed in her bra.
Bed bug detection dogs
Detection dogs are often specially trained by handlers to identify the scent of
bed bug
Bed bugs are insects from the genus ''Cimex'' that feed on blood, usually at night. Their bites can result in a number of health impacts including skin rashes, psychological effects, and allergic symptoms. Bed bug bites may lead to skin changes ...
s. With the increased focus on green pest management and
integrated pest management
Integrated pest management (IPM), also known as integrated pest control (IPC) is a broad-based approach that integrates both chemical and non-chemical practices for economic control of pests. IPM aims to suppress pest populations below the econ ...
, as well as the increase in global travel and shared living accommodations, bed bugs have become more prevalent. Detecting bed bugs is a complicated process because insects have the ability to hide almost anywhere. Detection dogs help solve this problem because of their size, speed, and sense of smell. Detection dogs use their unique ability to smell in parts per trillion in order to track bed bugs in every phase of their life cycle. They can find bugs in places humans cannot such as wall voids, crevices, and furniture gaps. Dogs are also a safer alternative to pesticide use. If detection dogs can find out exactly where bed bugs are located, they can minimize the area that needs to be sprayed.
The
National Pest Management Association
The National Pest Management Association (NPMA), is a non-profit trade association founded in 1933 that represents the interests of the professional pest management and pest control industries in the United States.[University of Kentucky
The University of Kentucky (UK, UKY, or U of K) is a Public University, public Land-grant University, land-grant research university in Lexington, Kentucky. Founded in 1865 by John Bryan Bowman as the Agricultural and Mechanical College of Kentu ...]
reviewed studies on bed bug detection dogs and concluded that although expensive for operators, they are a reliable source as long as they undergo the proper training. In another study, detection dogs had a 97.5% correct positive indication rate on identifying
bed bug
Bed bugs are insects from the genus ''Cimex'' that feed on blood, usually at night. Their bites can result in a number of health impacts including skin rashes, psychological effects, and allergic symptoms. Bed bug bites may lead to skin changes ...
s (''
Cimex lectularius
''Cimex lectularius'' is a species of Cimicidae (bed bugs). Its primary hosts are humans, and it is one of the world's major "nuisance pests".
Although bed bugs can be infected with at least 28 human pathogens, no studies have found that the in ...
'') and their eggs – with zero false positives – all while accurately distinguishing them from
carpenter ant
Carpenter ants (''Camponotus'' spp.) are large () ants indigenous to many forested parts of the world.
They build nests inside wood consisting of galleries chewed out with their mandibles or jaws, preferably in dead, damp wood. However, unlik ...
s,
cockroach
Cockroaches (or roaches) are a paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known as ...
es, and
termites
Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...
. They also successfully differentiated live bed bugs and viable bed bug eggs from dead bed bugs, cast skins, and feces with a 95% correct positive indication rate.
Bed bug detection dogs should be certified by a national organization like the World Detector Dog Organization (WDDO) or the National Entomology Scent Detection Canine Association (NESDCA). There are a few independent K9 bed bug inspection companies that have multiple certifications.
Wildlife scat detection
Scat is abundant in the wild and contains valuable data. Wildlife scat detection represents a fairly non-invasive method of study for many species where live-capture once predominated. Compared with other methods of scat collection, dogs are able to survey larger areas in less time at decreased costs. Research shows that detection dogs can find laboratory rats and mice in a large rodent-free area of 32 hectares (an extremely large area). Some specific types of feces that detection dogs have had success in identifying include
killer whale
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus ''Orcinus'' and is recognizable by its black-and-white pa ...
feces,
northern spotted owl
The northern spotted owl (''Strix occidentalis caurina'') is one of three spotted owl subspecies. A western North American bird in the family Strigidae, genus ''Strix (genus), Strix'', it is a medium-sized dark brown owl native to the Pacific No ...
pellets, and
salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...
s.
COVID-19 detection
Some countries have trained dogs to detect COVID-19. Australia has been using some of these in 2021.
Researchers in Paris in March 2022 reported in a preprint not yet peer-reviewed that trained dogs were very effective for rapidly detecting the presence of SARS-Cov2 in people, whether displaying symptoms or not. The dogs were presented with sweat samples to smell from 335 people, of whom 78 with symptoms and 31 without tested positive by PCR. The dogs detected 97% of the symptomatic and 100% of the asymptomatic infections. They were 91% accurate at identifying volunteers who were not infected, and 94% accurate at ruling out the infection in people without symptoms. The authors said "Canine testing is non-invasive and provides immediate and reliable results. Further studies will be focused on direct sniffing by dogs to evaluate sniffer dogs for mass pre-test in airports, harbors, railways stations, cultural activities, or sporting events."
Criticism
Accuracy
Australia
In 2001, the Australian state of
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
introduced legislation that granted police with the power to use drug detection dogs without a warrant in public places such as licensed venues, music festivals, and public transport (see
New South Wales Police Force strip search scandal
The New South Wales Police Force strip search scandal refers to an ongoing policing scandal surrounding the routine and arbitrary use of strip searches by members of the New South Wales Police Force.
Particular concern has centred around the us ...
). The law was reviewed in 2006 by the New South Wales Ombudsman, who handed down a critical report regarding the use of dogs for drug detection. The report stated that prohibited drugs were found in only 26% of searches following an indication by a drug sniffer dog. Of these, 84% were for small amounts of cannabis deemed for personal use. The report also found that the legislation was ineffective at detecting persons in supply of prohibited drugs, with only 0.19% of indications ultimately leading to a successful prosecution for supply.
United States
In 2011, civil rights activists claimed that detection dogs responses are influenced by the biases and behaviors of their handlers, which can hinder accuracy.
Another factor that affects accuracy is residual odors. Residual odors can linger even after illegal materials have been removed from a particular area, and can lead to false alarms. Additionally, very few states have mandatory training, testing, or certification standards for detection dogs.
This leaves people to question whether they are truly equipped to carry out searches.
Sniffer dogs can be trained to detect crop pests and diseases. A study by the US Department of Agriculture found that sniffer dogs identified trees infected with
citrus greening disease
Citrus greening disease (; or HLB) is a disease of citrus caused by a vector-transmitted pathogen. The causative agents are motile bacteria, ''Liberibacter'' spp. The disease is vectored and transmitted by the Asian citrus psyllid, ''Diaphorina ...
with 99% accuracy; they could detect infection as early as two weeks after onset.
Civil rights
Detection dogs give police the potential to conduct searches without cause, in a manner that is unregulated. They are often accused of being motivated more by the state's desire to be seen doing something than by any serious desire to respond to the dangers of drugs use. In June 2012, three
Nevada Highway Patrol
The Nevada State Police (NSP), formerly the Nevada Highway Patrol (NHP) from roughly 1949 to 2021, is the state police and highway patrol agency of Nevada, with state-wide jurisdiction.
The Nevada State Police is a division of the Nevada Departm ...
officers filed suit against
Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
's Director of Public Safety, alleging that he violated the police dog program by intentionally training canines to be "trick ponies" to falsely alert based on cues from their handlers (
Clever Hans effect
Clever Hans (German: ''der Kluge Hans''; c. 1895 - c. 1916) was a horse that was claimed to have performed arithmetic and other intellectual tasks. After a formal investigation in 1907, psychologist Oskar Pfungst demonstrated that the horse was ...
) so as to enable officers to conduct illegal searches of vehicles. The lawsuit claims that in doing so, he and other top Highway Patrol officers had violated the federal
Racketeer Influenced and Corrupt Organizations Act
The Racketeer Influenced and Corrupt Organizations (RICO) Act is a United States federal law that provides for extended criminal penalties and a civil cause of action for acts performed as part of an ongoing criminal organization.
RICO was en ...
(RICO Act).
In Norway, students were subjected to a drug search in their classroom by a detection dog. The students didn't have to be present in the room while the dogs searched; however, they were forced to answer questions by the police instead.
An article in ''Tidsskrift for strafferett'', Norway's journal of
criminal law
Criminal law is the body of law that relates to crime. It prescribes conduct perceived as threatening, harmful, or otherwise endangering to the property, health, safety, and moral welfare of people inclusive of one's self. Most criminal law i ...
, claims that such searches breach
Norwegian law.
Detector dogs have been used by secret police and security services to support campaigns of political persecution. For example, sweat collected from subjects following interrogation was used by the
Stasi
The Ministry for State Security, commonly known as the (),An abbreviation of . was the Intelligence agency, state security service of the East Germany from 1950 to 1990.
The Stasi's function was similar to the KGB, serving as a means of maint ...
to train dogs to respond to their scent.
See also
References
Further reading
NPR's ''All Things Considered'': Using Dogs to Sniff Out Bed Bugs''Fox Philadelphia: "Bed Bug Dog and Bed Bug Control Experts discussing use of Bed Bug Dogs"*Braverman, Irus. 2013.
Passing the Sniff Test: Police Dogs as Surveillance Technology" ''Buffalo Law Review'' 61 (81): 81–167.
*Blum, Binyamin. 2017.
The Hounds of Empire: Forensic Dog Tracking in Britain and Its Colonies, 1888-1953" ''Law and History Review'' 35: 621–65.
External links
*
{{Working animals
Dog training and behavior
Explosive detection
Scent hounds
Working dogs