K-9: The Nose Knows


One of the frustrations I have had since arriving in country is the lack of K-9 understanding by both military and contractors. It is not anyone’s fault in particular, but it leads to confusion about what the dogs are capable of and what exactly they tell us when they are searching.

Dogs search for odor, not for actual explosives

Dogs are trained to sniff for the odor of explosives. This does not mean that there are actual explosives at the source of the odor. For example, is someone borrowed your car and smoked in it (assuming you had never smoked in it before); the odor of the cigarettes would remain in the car for several days after the car was returned.

You might not be able to tell how much that person smoked in your car or how long before it was returned, just that the car still smells like cigarettes. This is similar to what happens when the dogs “alert” to the odor of explosives. We have no way of knowing (outside of a controlled training scenario) how much explosives were in a vehicle or how long ago they were removed.

Another thing to consider is what substances might smell close enough to explosives to gain the interest of the K-9. Ammonium fertilizer being transported in a diesel truck (Ammonium Nitrate)? Glycerin soap used around fatty meats (Nitroglycerin)? Both might resemble the smell of materials that the dogs are trained to sniff for but not actually be an explosive material.

Does this mean that the dog is wrong? No, it just means that the odor has lingered longer than the actual material or some combination of substances has triggered the dog’s interest.

Just because there isn’t a bomb, it’s not a false alert

The term “false alert” is used by people with little K-9 experience. In their mind, because the dog sits and nothing is found, the dog is wrong. Now I’m not saying the dogs are never wrong, but as I explained above, the odor of an explosive material can remain long after the item is moved. A seasoned handler should be able to tell you if the dog is responding to odor or just messing around.

A better term to use is “unproductive search”. This implies that the dog responded to odor, the handler determined that it was a legitimate response, and then a search was conducted of the area and nothing was found. It is important to treat these unproductive searches the same way every time, according to standard procedures, to prevent complacency.

The last thing we want is for the bad guys to see that we are no longer conducting thorough searches because so many have been unproductive. What better time to pass an actual device through a secure checkpoint.


If you are in a position where K-9’s are part of your duty assignment, take the time to ask questions about what you see and what you’re being told. While it may look obvious to you, there are unseen factors involved that might shed some light on what the K-9 is really doing.


~Frazier D Civilian Contractor EOD K-9 Correspondent

Frazier D
Frazier D

Frazier D was a police officer for 14 years, 8 as a K-9 handler. He is currently a Civilian Contractor bomb dog handler in Iraq.