My experience has been in the arena of combat tracking and mantracking, ranging from 40 years ago in Vietnam to present, working exclusively with a combat branch of the US military. We've proven that a lot of information pasted on the internet and at siminars are absolutely false, so choose your trainer with microscopic view.

Some of the questions that are asked time and time again by our handlers are: (1) Is there a 'base' human scent? Early in my career I would've said 'no,' but now, in my own mind, there's room for discussion. If not then why do scout dogs (air scenters to civilians) alert on any human presence? How can he/she distinguish one human scent from another and still define it as human without a base scent? Another possible answer to the question is (if there isn't a base scent) is that the dog indicates on a scent that is not common to the present surroundings, with the dog discounting all but human scent. Or, could it be that the alert on human scent is due to diet...meat eaters? Meat eaters is an interesting concept when we look at wild game naturally fearing the scent of humans. So, it's up for discussion...which theory is most correct, or is it a combination of all. I know that scientists have used all kinds of spectromitors etc to evaluate human scent, but at the same time those are the same folks who invented most modern combat technology...but still can't match that of the dog.

This is what I have read. I have not done the research myself, so of course I am parroting here:

Dogs are capable of determining, from the urine of another dog,

a) the sex of the dog
b) the age of the dog (puppy, adult, etc)
c) the health of the dog
d) the dog's diet
c) other things I can't remember now


Wolf pups will often not pee anywhere except around thier den because, as the theory goes, if a larger, aggressive animal is around, it will know there is a food source (puppies) nearby and endanger the whole pack. My 15 week old GSD will only pee in our yard and will hold it anywhere else. I don't know if this is the reason why, but it makes a certain sense. When the pups reach maturity and are an asset to the pack, as opposed to a liability, they mark on everything to tell others to stay away.

Some dogs can detect insulin levels in people, seizures and even cancer.

I mention these things because I think a dog's ability to decipher scent is an incredibly complex thing. Therefore, I think that it's safe to assume that they can detect a generic human scent.

Dogs can track specific game, ignoring other scents. Bird dogs do not run after any wild animal, neither do dogs used in deer hunting. They descriminate. These dogs are not trained to pick up on the specific individual animal, only the species. So obviously, a species has a scent...then more specifically, a individual scent.

 Quote: David Layne

Another possible answer to the question is (if there isn't a base scent) is that the dog indicates on a scent that is not common to the present surroundings, with the dog discounting all but human scent.

You obviously know more about tracking than I do, but I would say just from a psychological standpoint, determining what is human just by process of elimination is unlikely. For one thing, it's way too time consuming to weed through and reject thousands of scents. The other thing is that it requires them to reason, which is not something that has been demonstrated on very many dogs at all.

The boarder collie, well known for being a highly intelligent dog, had among its ranks a particular individual who knew the individual names of all of its toys (I don't remember how many exactly, but it was a significant number).

It got acclaim because when it was presented with a large number of items it knew and one it didn't know, and was told to retrieve it, it realized that the name of the item wasn't familiar and neither was this particular object so therefore it must be the requested object. This was reasoning. Not many dogs have been able to demonstrate reliably that they can do this (although I personally think many can).

At any rate, even if all dogs were able to reason by the process of elimination, there would be many instances where they took you to the *wrong* unfamiliar scent, IMO.

As for the meat eaters concept...that would make a funny study. I don't think many vegans hunt so it would be hard to say!

Impressive answer. I believe that at present we know very little about how a canine processes scent information, but what we do know is that they do it very well.

In our tests at Yuma, AZ (hotter'n'hell) we've found that almost all canine that are known for their FST abilities become fringe trackers/trailers due to surface temperatures, or they track by FST so slowly that they are not in our best interest...because panting and sniffing do not work concurrently.

Contrary to popular belief, we've found that scent lasts a very long time in the desert, unlike the 'five hour' concept that most of us have been told. We routinely track/trail 36-48 hour tracks, but I believe that much is due to the huge amount of bacteria found in desert soil (Not so long ago desert soil was considered to be sterile....soil analysis indicates that more bacteria exists in desert soil than in rain forest soil).

But, the fact remains that there are two types of animals...predators and prey. If we study skulls, we can easily see that predators have eyes in front so they do not become distracted, and to utilize their sight along with hearing and their olfactory to close on their prey (or quarry) by the fastest means possible. (eyes in front...likes to hunt). Prey, on the other hand, have eyes on the side of the skull. (eyes on the side...they run and hide). Predators range of eyesight is about 240 degrees while prey eyesight is between 300-320 degrees, allowing them the protection of an extraordinary range of sight. But, little of this has to do with why prey animals are born, it seems, with a natural fear of predators, even prior to any previous contact with predators. There must be a key that we've not yet found.

Very interesting questions and thoughts.

Hate to use my dogs as examples but this is my experience. When objects are lost by humans in our hay field (sunshades, knife, wallet) one of my dogs will start to alert 10- 20ft from the object by raising her hackles. When she finds the object she will either bring it to me or just carry it in her mouth. I have not trained her to do this so do not give any command for her to search because I didn't know there was an object to find. She does not indicate this way with animal scent will just follow the trail or urinate where they have been. Two of my other dogs alert to animal scent with raised hackles but, not to human scent, basically ignore human scent.

The whole scent thing with dogs truly is fascinating. Would love the opinions of others about how the temperament and traits of the dog enter into the equation?

 Quote: david layne

So, it's up for discussion...which theory is most correct, or is it a combination of all.

Its probably a combination of all. I believe the dogs' scenting ability is similar to our eyesight. From the moment we open our eyes, they send information to the brain. Our brain processes this information and interprets/categorizes it. We easily have the ability to discriminate between an infinite variety of differences in the environment using our eyes.

 Quote: amber morgan

You obviously know more about tracking than I do, but I would say just from a psychological standpoint, determining what is human just by process of elimination is unlikely. For one thing, it's way too time consuming to weed through and reject thousands of scents. The other thing is that it requires them to reason, which is not something that has been demonstrated on very many dogs at all.

I respectfully disagree. This is demonstrated hundreds of times per week just with our disaster SAR dogs during training. Our dogs search via air-scent to find hidden human subjects buried beneath rubble, etc. These dogs are able to detect what I would call "hidden" human scent. They must ignore all other human scent in the area, including other rescue workers, as well as an infinite number of other distractions and background scents. They must also ignore strong sources of residual human scent, which may be found in bedding or previously worn clothing. You will even see experienced disaster SAR dogs scent check human by-standers to make sure they are not the source of the scent the dog is picking up. In essence, they are weeding through and rejecting millions of scents to locate the strongest point of the target scent.

 Quote: david layne

Is there a 'base' human scent? Early in my career I would've said 'no,' but now, in my own mind, there's room for discussion. If not then why do scout dogs (air scenters to civilians) alert on any human presence?

See my paragraph above. There must be a "base" human scent. Otherwise, our disaster SAR dogs wouldn't be able to find human victims of disasters, right? Our dogs work without a "scent article" (it would be impossible to obtain) and find any hidden human scent within a given area.

Good discussion!

 Quote: konnie hein

I respectfully disagree. This is demonstrated hundreds of times per week just with our disaster SAR dogs during training. Our dogs search via air-scent to find hidden human subjects buried beneath rubble, etc. These dogs are able to detect what I would call "hidden" human scent. They must ignore all other human scent in the area, including other rescue workers, as well as an infinite number of other distractions and background scents. They must also ignore strong sources of residual human scent, which may be found in bedding or previously worn clothing. You will even see experienced disaster SAR dogs scent check human by-standers to make sure they are not the source of the scent the dog is picking up. In essence, they are weeding through and rejecting millions of scents to locate the strongest point of the target scent.

I understand where you're coming from here. But isn't that part of the dog's training, or at least a result of it?

As I said, I do believe that dogs reason and even many pet owners probably have good examples of when their dog has demonstrated this. It is a hard thing to measure, for sure, or even define.

 Quote: konnie hein

Its probably a combination of all. I believe the dogs' scenting ability is similar to our eyesight. From the moment we open our eyes, they send information to the brain. Our brain processes this information and interprets/categorizes it. We easily have the ability to discriminate between an infinite variety of differences in the environment using our eyes.

Very good analogy, and well put.

I absolutely believe there must be a base human scent. Cadaver dogs can also sift it out - sorting out human remains from that of other animals including carnivores. The uniqueness is such that they can even sort out human cremains from those of other animals.

If they can sort the scents of very dead humans from that of dead animals it seems targeting live humans vs other animals would be a cakewalk.

The dogs nose and olfactory lobes are MUCH MUCH MUCH more sophisticated than ours. Our eyes are much more sophisticated than theirs (though dogs excel at detecting motion) - - the combination of our eyes and reasoning ability and their nose and hunting ability is pretty impressive.

 Quote: Amber Morgan

I understand where you're coming from here. But isn't that part of the dog's training, or at least a result of it?

I guess you could say it is a result of the training, however, I'm not sure why that is entirely relevant. Basically we provide scenarios for the dogs (from very very basic scenarios in the beginning to complex ones when they become more advanced) and the dogs 'figure it out' (that's a very very basic description, I know). It is the dogs' drive to play with/tug/possess their toys, coupled with scenting ability and (I believe) ability to reason and discriminate between scents, that allow it to do what I described in my post above. So, yes, we provide the training, but the dog has to bring a lot to the table on its own.

 Quote: konnie hein

....I respectfully disagree. This is demonstrated hundreds of times per week just with our disaster SAR dogs during training. Our dogs search via air-scent to find hidden human subjects buried beneath rubble, etc. These dogs are able to detect what I would call "hidden" human scent. They must ignore all other human scent in the area, including other rescue workers, as well as an infinite number of other distractions and background scents. They must also ignore strong sources of residual human scent, which may be found in bedding or previously worn clothing. You will even see experienced disaster SAR dogs scent check human by-standers to make sure they are not the source of the scent the dog is picking up. In essence, they are weeding through and rejecting millions of scents to locate the strongest point of the target scent.

 Quote: david layne

Is there a 'base' human scent? Early in my career I would've said 'no,' but now, in my own mind, there's room for discussion. If not then why do scout dogs (air scenters to civilians) alert on any human presence?

See my paragraph above. There must be a "base" human scent. Otherwise, our disaster SAR dogs wouldn't be able to find human victims of disasters, right? Our dogs work without a "scent article" (it would be impossible to obtain) and find any hidden human scent within a given area.

Good discussion!

Konnie, I'm not in SAR and wasn't aware of all the elimination of scents a dog goes through in the search process (WOW), but what you said served to confirm to me what is my opinion on this issue, that there is a "base" human scent and that there is a process of elimination. Thanks for spelling out the some of the SAR process for dogs so wonderfully, very informative.

 Quote: Konnie Hein

 Quote: Amber Morgan

I understand where you're coming from here. But isn't that part of the dog's training, or at least a result of it?

I guess you could say it is a result of the training, however, I'm not sure why that is entirely relevant. Basically we provide scenarios for the dogs (from very very basic scenarios in the beginning to complex ones when they become more advanced) and the dogs 'figure it out' (that's a very very basic description, I know). It is the dogs' drive to play with/tug/possess their toys, coupled with scenting ability and (I believe) ability to reason and discriminate between scents, that allow it to do what I described in my post above. So, yes, we provide the training, but the dog has to bring a lot to the table on its own.

Well, I guess when I was talking about a dog demonstrating having reasoning capabilities, I was talking about independant of all training.

Many people have said that our ability to reason is one of the things that distinguishes us from other animals, and there have been many studies to try and prove or disprove this.

This is why the Border Collie I mentioned became so famous (he was even on Oprah, I believe..Oooo ). This dog demonstrated reasoning ability beyond training. Theoretically. You could argue that the owner taught him this sort of thing before she ever started talking him up!

So that's why I said that, while I do believe that dogs reason to a certain extent, it's hard to define and harder to prove that it isn't a result of training. At least in contolled studies. And with a very tightly controlled definition of reasoning, which is always up for debate!

Sorry, OP, to get slightly off topic, just wanted to clarify my point.

And Konnie, this is NO way says that your dogs aren't reasoning to a certain extent and it in NO way makes what they do any less impressive. I saw many articles and short films about the S&R dogs post 9/11 and it was really incredible and humbling.

If you'd like to continue this discussion in a PM I'd be happy to, because it is interesting but I don't want to hijack this already very interesting thread! Also, it's been discussed on this board before, here:
http://www.leerburg.com/forums/ubbthreads.php/ubb/showflat/Number/77916/site_id/1#import and it was ultimately locked, so I don't want this thread to suffer the same fate. Very good reading though.

It's too bad we can't reason with dogs more easily. Otherwise it would be a lot easier to make my dog understand why I leave him in the crate when I go out!