In the hours after a disaster strikes — from events like 9/11 to earthquakes and tornadoes — it’s common to see rescue dogs treading carefully among the rubble, using their agility and heightened sense of smell to search for survivors. When efforts turn from rescue to recovery, organizers enlist different dogs: those trained to find the remains of people who did not survive.
Cadaver dogs, also known as human remains detection dogs, have become essential in police investigations too when searching for missing persons or evidence of a murder — with or without a body.
It takes a specially trained dog — and a special kind of person — to do the work of searching for human remains, Jason Purgason, who runs Highland Canine Training in North Carolina, told me in a recent interview.
For more than 25 years, Purgason has been training dogs to find all kinds of things, including bumblebees, bat guano, people who are lost or in need of rescue, and, yes, cadavers.
Read on to find out more about training these incredible dogs and the people, usually volunteers, whose grueling work brings challenges and rewards — including closure to families of missing loved ones. (Warning: Some details are gory — but they’re important to be aware of if you’re considering becoming a cadaver dog handler yourself.)
What do cadaver dogs do and how do you train them for this work?
Jason Purgason: Human remains detection encompasses three types or aspects of training. The standard cadaver dog, sometimes called a “field cadaver dog,” is trained to go out and search for, locate, and alert to human decomposition — usually in wooded areas, big fields, national forests, maybe even in people's homes or vehicles or barns.
The second type is called a “disaster cadaver dog,” and that's similar to the dogs that were used during 9/11, later on in the process. Those dogs are utilized once an operation moves to what is considered a recovery operation and no longer a rescue operation. So their skill level is actually a little higher than those initial dogs I was talking about, in that they can work in even more demanding environments: rubble piles, areas where there's been a natural or man-made disaster, glass buildings, glass structures, that sort of thing.
And then the third type is the most difficult to train, only because it requires a lot more time and a lot more resources, and that's what is referred to as a “water cadaver dog.” And that's a dog that will locate decomposition in aquatic environments, lakes, rivers, streams, etc.
OK, how is that even possible? How do you train them to search in water?
The short, very nonscientific version of it is when humans decompose that tissue will off-gas, right? The body will [expel] gas. … Because those gases are lighter than water, they will oftentimes — not always — rise to the top. And now a dog's able to detect that faint smell and be able to sort of narrow down where their body is underwater.
What makes a good candidate for a cadaver dog? Are there specific breeds that are better than others?
Breeds, sex — all that's fairly unimportant. We look for a couple of things. We look for drive — that dog's motivation to engage with prey items, toys, etc., and their ability to hunt for it for extended periods of time. So we throw a toy in tall weeds: How long will they search for it, initially?
And then we look at overall trainability, and we look at overall environmental stability. How do they do in different environments? How social are they? And that's really what's important. Again, size, color, breed — that stuff's not as important, particularly with cadaver dogs.
What about the age of the dog?
Age does play a factor. We like dogs that are usually between a year to 2½ years old. Can we train a 5-year-old dog? Yes. But you know, that's a lot of time and resources going into a dog that is probably going to have a fairly short working life, if we're starting when it's 5, 6, or 7, for example. And that's why we like to get them a little younger, just to get a little more overall working life out of them.
What is the typical working life of a cadaver dog, and what happens when they retire?
Generally, depending on the breed and the age at which they start, those dogs can work sometimes 8, 10 years, as long as their health holds up. What happens when they retire? Generally, they go and live out their days as a pet in that handler's home.
Say somebody has a 1½-year-old dog they just adopted from a shelter and they want them to be trained as a cadaver dog. What do they do?
My suggestion would be for them to reach out to a professional dog trainer who has some experience with detection dogs, similar to somebody like me, and have that dog evaluated to see if it has the aptitude, the requisite drive, trainability, and sociability to do this type of work. Because if not, what we see is people who spend a lot of time and a lot of effort really trying to fit a square peg into a round hole. Unfortunately, when I evaluate dogs for people, a lot of times — not always, but a lot of times — I really have to have them make a decision: Do you want a cadaver dog, or do you want this dog that you currently own to be a cadaver dog? Because they may not be the same.
Once you’ve found a good candidate, what do you use for training aids?
Without getting too deep into the weeds, there are a couple choices in the industry. One of them is terrible. The other two are pretty good.
To imprint and train cadaver dogs, we historically have used human remains — real human remains. And we imprint the dogs on five different odors: blood, bone, hair, teeth, and tissue.
There are chemically formulated training aids out there. The newest one is a product that was developed by a company called ScentLogix — we've been using their chemically formulated training aids for a variety of different things for more than a decade, whether it be drugs, explosives, bedbugs, whatever, and I found that to be a really good option — in all reality, probably better than the real thing for a lot of different reasons. For most people getting into the industry, that is just going to be a lot easier to access. Getting access to human parts can be incredibly, incredibly challenging for people, for a lot of different reasons.
Could you tell me about some of those challenges?
Well, there's a lot of ethical questions that come up when you're trying to obtain body parts. Certain states have rules and regulations against people possessing human body parts, certain body parts. So anybody looking to get into this should definitely understand their local or state regulations and rules about possessing human remains and human body parts. The last thing they want to do is find themselves getting in trouble trying to help.
A lot of people working in the medical field, and that sort of thing, often are really not inclined to bend over backwards to help handlers procure training aids. And then the other issue with using real training aids is you're limited in the types and quantities that you can get, and that creates a lot of challenges too. Because most of the time — not always, but most of the time — we're trying to train this dog to find the entire human, or at least the majority of a decomposing human, and that can be huge and overwhelming compared to the training aids that we're likely to be able to procure for our imprint in a training.
So I assume you're not grave digging...
No [laughs]. So for example, you end up hooking up with a dentist or a couple of dentists, they can get you teeth from extractions and those sorts of things. Hair is probably one of the easiest to get. I talk to some barbers and folks — there's a process, and there's some processing that needs to be done with hair just to remove soaps and shampoos and other products from it, but it's usually the easiest one to obtain. Blood, tissue, and bone can be a little more difficult. Human bone, believe it or not, you can actually purchase online.
Are you serious?
Yep, you can look it up — you can purchase online, usually out of Asia. [Editor’s note: I did look it up — there are a surprising number of human bone dealers.]
Oh my god. Does your connection to law enforcement help you? Are you allowed to go to a crime scene and train a dog in that way?
No, that's generally not allowed — really, period. And again, that's what can create some real boundaries. But let's just say you had somebody who was deceased for whatever reason out in a field, like an open rural area. In the event that that individual's out there for some period of time, they're gonna start really sort of decomposing, especially when they get into that bloat phase. And they're going to create, for lack of a better way to put it, they're going to create goo. And that goo is going to leach into the ground. And that goo is pretty pungent, even after that body has been removed. With the right contacts, the cadaver dog handlers can sometimes get the phone call to go out and work on that large pile of goo once law enforcement has released that scene. But again, the body's not there — just sort of remnants of the body.
OK, you mentioned a third “terrible” training aid.
Pig, believe it or not. People resort to using pigs and pig tissue and pig parts to train cadaver dogs because the pig is close in size to the human mass and it has hair and it has skin. So cadaver dog handlers got the idea that they could use it when they couldn't find training aids, and that is absolutely not a good idea. So I will discourage anybody from doing that.
Why is that exactly?
Well, you're just going to train a dog that's good at finding dead pigs. A dead pig and a dead human just don't smell the same.
Do you work directly with law enforcement?
Generally what we're doing is training and supplying dogs and training handlers who go out and do that. We oftentimes find that a lot of law enforcement teams don't have cadaver dogs available to them, meaning they don't have their own in-house. So they oftentimes have to rely on civilians who are willing to provide the dog and time to come out and do the work.
Do you know if the police are paying these people and if so, like, what the range is?
Here's the bad news for some people. The reality is, generally no. They may at times cover their costs — fuel costs, travel costs — but [cadaver dog handlers] are really not making any money. They're probably losing it.
I met a cadaver dog handler a few years ago who said she volunteered because she felt like she was making a difference.
And that's why most people do it. But being a cadaver dog handler is not for everybody. And on some level, you know, it really — excuse my language — it really sucks. Because you show up with a cadaver dog to a potential crime scene or a place where you're called by law enforcement to search for somebody's missing husband or missing wife or missing son or whatever the case may be, it doesn't really matter which answer you come back with — it's not gonna be a good one. You're gonna come back with one of two answers: You found something or you didn't find something. And the reality is that either of those answers is generally not going to be great.
So a lot of those people do offer their dogs and services up because they want to try to bring closure to families. And they want to try to assist law enforcement in finding these individuals as soon as they can to try to help further their law enforcement investigations, if that's the case, etc. But you know, they're not compensated for what they probably should be. They oftentimes put years and tons of work and effort and travel into getting these dogs trained and keeping them trained. I commend people who handle cadaver dogs. It is a lot of work and, like I said, the outcome for them is often not a great one.
People who are interested in learning more about it or getting involved in cadaver dog handling really need to just think long and hard about it. Because, again, not everybody is suited to find decomposing bodies. It's graphic. It's pungent. I'm not trying to be super gross, but when you find a body and it's vibrating with insect activity, that can have some looong-lasting effects on people who are not prepared for things like that.
But there's also a need for dog handlers to find people who are still alive, that is just as rewarding.
This interview has been lightly edited and condensed.