
A detection dog or sniffer dog is a dog that is trained to use its senses to detect substances such as explosives, illegal drugs, wildlife scat, currency, blood, and contraband electronics such as illicit mobile phones. The sense most used by detection dogs is smell. The smell from the detection dogs are more enhanced than the average dog. They are trained to have this great sense of smell. Hunting dogs that search for game, and search dogs that work to find missing humans are generally not considered detection dogs. There is some overlap, as in the case of cadaver dogs, 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.

The Alpine Spaniel is an extinct breed of dog which was used in mountain rescues by the Augustinian Canons, who run hospices in the region around the Great St. Bernard Pass. The spaniel was a large dog notable for its thick curly coat. One of the most famous specimens of the Alpine Spaniel is Barry, however his preserved body has been modified on more than one occasion to fit with descriptions of the extinct breed from earlier time periods. Due to the conditions in the Alps, and a series of accidents, extinction was discussed as a possibility by authors during the 1830s, and at some point prior to 1847 the entire breed was reduced to a single example due to disease. Evidence held at the Natural History Museum in Bern show that two distinct breeds of dog were being used in the area during this time period.

R v AM, [2008] 1 S.C.R. 569, 2008 SCC 19, is a constitutional decision by the Supreme Court of Canada on the limits of police powers for search and seizure. The Court found that police do not have the right to perform a sniffer-dog search of public spaces when such search is not specifically authorized by statute. In this case, a student's section 8 rights under the Canadian Charter of Rights and Freedoms ("Charter") were violated when a police officer sniffer-dog searched his unattended backpack in the gymnasium of his school finding drugs in his possession.

Barry der Menschenretter (1800–1814), also known as Barry, was a dog of a breed which was later called the St. Bernard that worked as a mountain rescue dog in Switzerland and Italy for the Great St Bernard Hospice. He predates the modern St. Bernard, and was lighter built than the modern breed. He has been described as the most famous St. Bernard, as he was credited with saving more than 40 lives during his lifetime, hence his byname Menschenretter meaning "people rescuer" in German.

Conservation Canines (CK9) is a non-profit organization that trains detection dogs and their handlers for the purposes of wildlife research. It is part of the Center for Conservation Biology at the University of Washington. Since 1997, led by Dr. Samuel Wasser, Conservation Canines has worked internationally with species including the Pacific Pocket Mouse, the Jemez Mountains salamander, Killer whales, and Tigers.

The Defence Animal Training Regiment (DATR) is a training establishment, based in Melton Mowbray, east Leicestershire. It trains animals, of which the most numerous are dogs, for all three armed forces. Its headquarters are also the principal base of the Royal Army Veterinary Corps.
The English Springer Spaniel is a breed of gun dog in the Spaniel family traditionally used for flushing and retrieving game. It is an affectionate, excitable breed with a typical lifespan of twelve to fourteen years. They are very similar to the Welsh Springer Spaniel and are descended from the Norfolk or Shropshire Spaniels of the mid-19th century; the breed has diverged into separate show and working lines. The breed suffers from average health complaints. The show-bred version of the breed has been linked to "rage syndrome", although the disorder is very rare. It is closely related to the Welsh Springer Spaniel and very closely to the English Cocker Spaniel; less than a century ago, springers and cockers would come from the same litter. The smaller "cockers" hunted woodcock while the larger littermates were used to flush, or "spring", game. In 1902, The Kennel Club recognized the English Springer Spaniel as a distinct breed. They are used as sniffer dogs on a widespread basis. The term Springer comes from the historic hunting role, where the dog would flush (spring) birds into the air.

Florida v. Harris, 568 U.S. 237 (2013), was a case in which the United States Supreme Court addressed the reliability of a dog sniff by a detection dog trained to identify narcotics, under the specific context of whether law enforcement's assertions that the dog is trained or certified is sufficient to establish probable cause for a search of a vehicle under the Fourth Amendment to the United States Constitution. Harris was the first Supreme Court case to challenge the dog's reliability, backed by data that asserts that on average, up to 80% of a dog's alerts are wrong. Twenty-four U.S. States, the federal government, and two U.S. territories filed briefs in support of Florida as amici curiae.

Florida v. Jardines, 569 U.S. 1 (2013), was a United States Supreme Court case which resulted in the decision that police use of a trained detection dog to sniff for narcotics on the front porch of a private home is a "search" within the meaning of the Fourth Amendment to the United States Constitution, and therefore, without consent, requires both probable cause and a search warrant.

Frida the Rescue Dog is a Golden Labrador Retriever in the Mexican Navy (SEMAR). She was deployed in the event of natural disasters to help the rescue efforts. Frida has helped save the lives of people buried under the rubble of buildings that collapsed in the 2010 Haiti earthquake, victims of a landslide in Guatemala in 2012, after the explosion of the Torre Ejecutiva Pemex in Mexico City in 2013, the 2016 Ecuador earthquake and the 2017 Puebla earthquake in Mexico. Reports have suggested that she has located more than 52 people.

Jet of Iada a.k.a. Jet was a German Shepherd Dog, who assisted in the rescue of 150 people trapped under blitzed buildings. He was a pedigree dog born in Liverpool, and served with the Civil Defence Services of London. He was awarded both the Dickin Medal and the RSPCA's Medallion of Valor for his rescue efforts.

R v Kang-Brown, [2008] 1 S.C.R. 456, 2008 SCC 18, is a constitutional decision by the Supreme Court of Canada on the limits of police powers for search and seizure. The Court found that police do not have the right to perform a sniffer-dog search of public spaces when such search is not specifically authorized by statute. In this case, a suspect's section 8 rights under the Canadian Charter of Rights and Freedoms ("Charter") were violated when a police officer stopped him at a bus station and sniffer-dog searched his bag finding drugs in his possession.

Lex was the first active duty, fully fit military working dog to be granted early retirement in order to be adopted. Working for his United States Marine Corps handler Corporal Dustin J. Lee in the Iraq War, he was wounded in an attack that killed Lee, and subsequently awarded an honorary Purple Heart.

The National Explosives Detection Canine Team Program is a program administered by the Transportation Security Administration which uses law enforcement and TSA-run explosive detection dog teams to detect explosives in transportation environments.

Sarbi was an Australian special forces explosives detection dog that spent almost 14 months missing in action (MIA) in Afghanistan having disappeared during an ambush on 2 September 2008. Sarbi was later rediscovered by an American soldier, and was reunited with Australian forces pending repatriation to Australia. Her name is sometimes spelled 'Sabi'.

Search and rescue dogs are valuable after natural disasters, mass-casualty incidents, and for locating missing people. Dedicated handlers and well-trained dogs are required. Search and rescue dogs are typically worked by a small team on foot.

Snowy RWP, also known as Commando Snowy, was a Golden Labrador Retriever who served as a tracking dog for the Sri Lanka Army during the Sri Lankan Civil War. Snowy was attached to the 4th Commando regiment and handled by Lance corporal D. H. P. Sampath. After serving in various fronts of the war, Snowy was injured by a grenade on 15 March 2008 while tracking a LTTE infiltration unit in Kambilioya, Weli Oya. Snowy received a Rana Wickrama Padakkama medal for his actions, the first dog to receive such an honour in Sri Lankan military history. He died on 24 May 2011 while recuperating from injuries received during a mission.

The Sulimov dog, also known as the Shalaika, is a jackal-dog hybrid originating in Russia from an initial hybrid between two Lapponian Herders and two Turkmenian golden jackals. The breed was developed by Klim Sulimov for Aeroflot airline. The breed has primarily been used for airport security as sniffer dogs.