A detection dog is a dog that is trained to and works at using his senses (almost always the sense of smell) to detect unusual substances such as explosives or narcotics. Hunting dogs that search for game and search dogs that search for missing humans are generally not considered detection dogs. There is some overlap in cases like cadaver dogs that detect human remains.

Detection dogs have been trained to search for many substances including the following:

• Agricultural produce
• Crime Evidence
• Drugs
• Explosives
• Human remains
• Termites