Most people think canine scent detection is around 90% to even 100% accurate. But I’m going to tell you just how accurate K9 detection for bed bugs in Ventura really is overall.
Before I had ever worked with K9 detection for bed bugs, I was under the impression that their accuracy was unparalleled. That a dog’s sense of smell works wonders at identifying hidden or unseen items is a common idea in society and is reinforced by their use in law enforcement. However, once I was hired to do objective quality control and testing I discovered that dogs were unreliable and that their performance varied from day to day.
If someone suspects they have bed bugs but can’t find any solid evidence of an infestation, a K9 inspection might sound like a good way to get reliable confirmation. But I’m going to show you evidence to the contrary so you know it’s not only my personal experience or bias that I’m basing my opinion on.
Can Dogs Really Detect Bed Bugs in Ventura?
We’ll first examine a very thorough study by Cooper, Wang, and Singh that you can find for free here.
Dr Cooper is a well respected bed bug and pest control researcher, and his findings are consistent with other studies I’ve seen from other industries. I know many people won’t read beyond this point, so I’m starting here because it’s the most relevant information on the subject.
First, the mean detection rate was 44%. That is an alarming number considering how accurate people think K9 teams really are at finding bed bugs in Ventura.
Second, the study found, “canine detection teams evaluated on multiple days were inconsistent in their ability to detect bed bugs and exhibited significant variance in accuracy of detection between inspections on different days.”
Third, “There was no significant relationship between the detection rate and the length of time the team had been working together and whether the team was certified.”
Finally, “False-positive alerts can result in significant direct and indirect costs. Had all of these units been treated based upon the results of the dog inspection, the direct treatment costs are likely to have exceeded $13,000.”
A second study invited 18 different canine teams from different law enforcement agencies to a church for a test. A church was used because it’s less likely that people bring contraband items like drugs or bombs into a church, lowering the chances a residual or “stale” odor.
Researchers found that the K9s falsely alerted their handlers to the presence of drugs or explosives over 200 times! In actuality, the researchers never brought any contraband items or explosives into the church. They just wanted to see if they would get false positives. In fact, there were false positive alerts by K9 teams in every room they inspected!
My own take on the results from these studies is that dogs are simply dogs. Their ability to detect scent is excellent but that doesn’t mean they will consistently provide dependable results.
Some dogs get fatigued. Some dogs get distracted. Some dogs get confused by inconsistent training or handler error. “Certified” is a meaningless term in my estimation because once that dog leaves the training area and the certifying instructors it will be subject to the handlers and caretakers who often don’t have the same level of skill in managing the dog’s performance. This results in confused dogs or dogs being trained improperly.
All of these factors chip away at the overall accuracy rate of K9 units. That being said, the research team in the Cooper study asked an important question: “Does a company have any incentive to replace a bed bug K9 that alerts when bed bugs aren’t even present?”
Since the study found that false positive bed bug detection could have generated substantial income (estimated around $13,000), would management view a dog as “broken” or unreliable? Do they have the training or procedures in place to notice false positives and do they even have the financial incentive to identify the difference?
If you proceed with a K9 inspection for bed bugs, be sure to ask the hard questions:
- Ask for visual confirmation.
- Ask to see the bed bug the dog detected.
- DO NOT sign up for bed bug treatment if the only evidence is a K9 alert.
- Get an objective second opinion from an experienced specialist if they cannot show additional evidence.
Let’s Examine the Evidence
So what conclusions do I draw from these two studies?
I think there needs to be further research on the topic, but I also think we can at least say there’s evidence of unconscious human cues that inadvertently influence what K9s identify. These cues could be influencing the dogs to alert or more heavily scrutinize something. Common perception is that these dogs are using only scent to detect, making it an objective process, but dogs want to make their handlers happy so they’re incentivized to find what may not really be there.
Dogs are influenced by their handlers in ways they may not be aware of and this also chips away at accuracy. Another thing to consider is that these are law enforcement K9 teams. Their standards are significantly higher than you’re likely to encounter with a pest control handler team.
Finally, let’s take a look at a few quotes by Dr. Lawrence Myers, an expert in this field. (You can read more about him here.)
“The standard measure of a dog’s accuracy is what it finds. The best programs subtract from that score the number of false alerts, but most do not and so they have no accurate measure of their dogs’ reliability.”
“In any year, 35 percent of detection dogs temporarily lose their sense of smell because of illness, tooth decay or other physical problems.”
“Dogs want rewards, and so they will give false alerts to get them. Dogs lie. We know they do.”
“There are limits on dogs’ performance that are frequently overlooked. Poor handlers alone can cause dogs’ vaunted accuracy rate of 85 percent to 95 percent to plummet..”
My Final Conclusion
There are mountains of evidence that dogs vary in their scent detection accuracy. I’m not saying dogs don’t have their place in detection work but I do want people to understand their inherent limitations and how that affects their accuracy. I think the general public gives K9 detection more trust than it currently deserves.
I frequently get angry dog handlers emailing me that their dog is an exception. I trust you and believe you. My goal with this article isn’t to take away from those that deserve credibility, but we need to study those top 10% performers and determine how to get the rest of the handler teams up to those same standards. Until we do, it’s the unsuspecting public that bears the consequences of false detections and the costs they incur.