Arson detection dogs, also known as accelerant detection dogs, are a type of working dog employed by police officers, fire marshals and forensics investigators in order to help determine the origin of a fire, and how the fire spread. Determining the origin of a fire is extremely important, but can also be extremely difficult. For a human investigator, finding evidence amongst the charred black remnants of a fire is a long and arduous process. The investigator will often take samples of burnt debris and have them sent to a lab for analysis. Using the superb sense of smell of an accelerant detection dog, investigators are able to find relevant samples and evidence in a fraction of the time it would have taken them otherwise.

Detecting accelerants amongst charred debris is no easy task. For a human investigator, even the otherwise distinct odors of gasoline or alcohol are easily masked by the pungent scent of burnt of plastic or house paint often found at the scene of a fire. This is made even more difficult by that fact that many accelerants evaporate quickly. On the other hand, arson detection dogs are able to pinpoint even minute particles  amongst  a vast array of other scents. These dogs must undergo rigorous training so that they know which scents to respond to and whether to indicate passively or aggressively. Training is an ongoing process in order to ensure that they are kept accurate throughout their entire careers. An arson detection dog is often able to identify a long list of accelerants ranging from acetone to rubbing alcohol to lamp oils. The identification of any of these substances can help an investigator determine if a fire was accidental, an attempt at insurance fraud, or even an attempted murder.

The dogs used for accelerant detection must be extremely intelligent and loyal. The most common breeds of dog used for this purpose are working breeds such as the Labrador Retriever, German Shepherd or Belgian Malinois. Due to the nature of the work, a dog with a calm and patient temperament is preferred. Most arson detection dogs are trained to indicate passively to insure that potential evidence is not disturbed.