In the 1980s, the United States Bureau of Alcohol, Tobacco, and Firearms led the way in reintroducing dogs to active roles in the fire service by training the first accelerant-detecting canine. A yellow Laborador named Nellie was the first dog trained as part of a pilot program in 1984. Nellie's performance was validated by the American Academy of Forensic Sciences. In 1986, ATF established the National Canine Accelerant Detection Program. Mattie, the first "operational" canine was deployed that September. Both dogs were acquired from guide dog programs.

Canines can pinpoint traces that escape electronic detection. Mechanical hydrocarbon detectors are sensitive to gasoline components in parts per million (ppm). The smallest amount detectable by dogs is .01 micro liters, or 1,000th of a drop, of 50% evaporated gasoline, 100% of the time. Also, a canine can differentiate between products of combustion and similar chemical gases found at fire scenes from true accelerant's, which mechanical detectors cannot.*

Canines are more adaptable and more accurate than mechanical equipment. This accuracy can help pinpoint the location of accelerant's in a shorter time, thereby reducing the field time of investigators searching and processing a fire scene. The use of canines can reduce the number of samples that need to be collected and tested. It is also documented that samples submitted from canine teams for laboratory analysis result in a positive test for ignitable liquids over 90% of the time, compared to 30% for the investigators alone.*

*Excerpted from http://www.dallasfirerescue.com/k9.htm