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Discussion Starter #1
I am not sure if this would fall under SAR or not, so I am posting it here.

We have a missing man from the local area. They have brought in a cadaver dog to search an area he was last seen in. There was an article about the dog in the local newspaper. The handler explained how he worked on land and water. He stated the last body they found was under 40 ft. of water. I knew about ground searching but was not aware they could detect in water.

I found that fascinating. Anyone know much about this? Is there a time period. I know usually after a couple of days the body rises to release gases, then goes back down. How does he indicate? What are the limitations or issues?
 

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Hopefully NancyJ see's this. She works an HRD dog and trains on water. I do live scent, but 2 of my teammates do HRD and at least one is certified for water work. They will work from a boat and the dog has a bark alert. That is the extent of my knowledge LOL.
 

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I have been to some water trainings and have read about the subject, but have not trained my dog for that yet.

When a body decomposes underwater, it releases oils, gases, etc. that can be detected by a dog as scent on the surface. There are a lot of variables that affect the decomposition process, so it is difficult to quantify the limitations, but I believe some bodies have been located by dogs years after they went missing, and some in quite deep water.

Usually the dog and handler work from a boat. They travel a grid pattern in the area and if the dog gets into a cadaver scent plume it will display its natural alert behavior such as pawing at the water, whining, or some other action that the handler has learned to read. The handler interprets this behavior and guides the boat into the direction of stronger scent. When the scent is at its strongest, the dog performs its trained alert behavior, which might be barking or lying down to tell the handler that is where the source of the scent is coming from.

When a dog has alerted on a location, often a second dog will be brought in to work the area independently in order to confirm it. If so, then divers are advised where to look. With no water current or wind, the body could be directly below, but the handler normally has to interpret the conditions to predict where the body might be based on where the scent is the strongest at the surface. There is a lot more to it than this, but hopefully this gives you an idea of what is involved. The Cadaver Dog Handbook has a chapter devoted to water searches.
 

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Discussion Starter #4
Thanks. I thought it was interesting.

I wonder if they will use this ability there is a theory he may have gone into the water (his glasses were found by the shore) Several dives of the area have turned up nothing, however, the water is very shallow on both sides of a deep channel. The channel has a strong current. The body (if there is one) may very well be being washed in and out.

I wish I had gone out to meet the handler.
 

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They can either work the dog from a boat or from the shore. If the man was in the water and has bounced along the shallower part of the area the dog may pick it up. If the water is swift moving in the center and the subject travelled there, then the dog may pick it up down stream a very long way and it can be difficult to work. If the handler is experienced in working water missions, they will be able to let you know how the area should be worked.
 

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Is the area tidal? If it is then it also will affect the way the area should be worked.
 

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I used to do drownings with my old dog who is gone now. The only real difference between detecting human remains on land vs water is there are thermoclines in most deeper bodies of water that act like a pane of glass blocking the scent. Otherwise, water is just thick air. Depending on how wide the body of water is and the wind direction, you can work it either from shore or from a boat.

I'm surprised that dog was able to have a find in 40 ft of water due to the thermoclines. There must have been quite a current or they were dragging the bottom to break it up or the body was very near the edge.
 

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I saw this on tv some time. They drive the dog around a lake in a boat, but I forgot the details. Dogs have amazing noses, don't they. I swear my dogs can smell the hotdogs from the back of the yard with the patio doors closes.
 

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Discussion Starter #9
That is interesting about the thermocline. I am a diver, although a very new one, and have experienced them but I can't remember how far down they usually are. I thought about 30 ft.

I still find it hard to wrap my head around it being the same as land. Of course I have little experience in tracking on land. I do realize that SAR tracking is different that the way a Police dog would track. If I remember correctly, SAR is more air scenting. I would just imagine the water would be so much more difficult to track because of current on surface can be different below, plus the wind above the water. It would also be so much more demand on the handler to interpret where to go as the dog just can't go in the direction he wants himself. I would love to have the opportunity to take part in a seach.
 

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Tracking or trailing and HRD (Cadaver searches) are so different you can't even relate them to each other. Most police k9's come from a sch. background and training where the learn to track (go step to step). Most SAR dogs trail, they do not track. Trailing is following the trail of scent coming off the subject. They may not necc. follow exactly where the foot falls are (which a tracking dog will do) if the wind blows the scent 5 or 10 feet off where the subject walked then the dogs work with that. Air scent work is completely different again, but often you will find that a good air scent dog will often follow a trail if they come across it. You cannot trail on water, we have done air scent problems from boats where we work the shore line untill the dog gets scent of someone on land, then put the boat into shore and work the problem from there. Have been very successful with this type of exercise. Mostly we do HRD from boats. There are some great books that explain how it works. Basically as the body is in the water cells ect are constantly coming off and cone out from the body as they rise to the surface. As air passes over the surface of the water it picks up the scent and if you are working the dog over that area the dog can pick up the smell. Sometimes the dog will drop its nose and get the scent from the water itself and sometimes that is not necc. It is fantastic how the dogs work and how they use their nose. I never get bored or tired of watching any of the dogs work out a problem in training or work on a search.
 

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I knew they were different, but not sure how. I know it is a silly question but trailing, would that be when they are given the scent of a person they are looking for and follow it? What would air scenting be used for?

I have done track work and understand how that works, but am curious at other types.

I agree with you on the dogs work. I would love to have an opportunity to watch this. I see you have a HRD, SAR and trailing dog.

I know another poster mentioned a book, do you have any other suggestions, I would like to read more about it.
 

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Just got back from training
We were going to do water training tomorrow but figured the roads were too icy and it was going to be below 20............

Basically, they way we do water is the dog "steers the boat" We train the dog to work on the front of the boat and work the scent cone during training enough *by moving in and out of it that the dog learns to move its body in the direction of the scent. When we get over source the dog flips around and starts to work back.

The thing that makes water from a boat a little more complex than land cadaver is the dog is constrained by the boat as they cannot pinpoint source - the driving the boat method really helps. We are not requiring a trained alert but rely on body language and the hook back to walk the gunnels.

Some people let the dog jump in and circle the scent - they will do that but there can be dangers in letting the dog do this.

For thermoclines - we have a temperature device you can drop to the bottom and it will take the temperature every 5 feet. When water temps are below 40F there is not much decomp. In really deep cold water the body may not float due to pressure.

If you have a thermocline you have to break it up. If it is not too deep a speed boat can do it. If it is deeper you can drag an anchor through it etc.

It is very interesting because even lakes can have currents underneath so what is going on underneath will influence where the scent comes out. If you really want to see it - take some smoke bombs out and throw them in a lake!!!!! (They work underwater)
 

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Originally Posted By: novarobinI knew they were different, but not sure how. I know it is a silly question but trailing, would that be when they are given the scent of a person they are looking for and follow it? What would air scenting be used for?
Well it is not really all that different to the dog - the problem with only trailing is that after a certain amount of time the trail starts to fade but, if the person is still alive, they are constantly sheeding scent which can be airborne. Early in a search ops you want those trailing dogs out there but as the search gets older (a few days) you want the air scent dogs scannig for scent. The reality is dogs follow scent to its source - trailing dogs air scent and air scent dog trail.

There is a current of air moving from our feet up and over our head. Groups of skin cells called rafts that fall off our body is carried in the current**. Imagine a fountain of scent coming off of our head - some falls to the ground. Some is picked up and carried on air currents, often for great distances. We have had some problems where the dog picked up airborne scent over 1/2 mile away.

When a dog is trailing they are picking up scent mostly from the ground in the general area where the person walked - sometimes not exactly where they walked, as described in a previous post. There is also scent associated with the footfall path (butyric acid from feet, crushed vegetation etc.) but the trailing dog follows the specific scent from that person - alhtough they may use other information in the track but we really have not been able to crawl into a dog's brain to figure out all that is going on.

Airscent dogs can be trained two ways - to find any human scent or to find the scent of a specific person. Those that are scent discriminating use a scent article and are usually started in trailing until they get down the concept that they need to find the person associated with the scent article. An airscent dog is gridded+++ in an area to pick up airborne scent, and they work from areas of lower to higher concentration.

Hope that is interesting. Some good books I like are are Syrotouk, "Scent and the Scenting Dog" which is an old classic, the ARDA book -"Serach and Rescue Dogs, Training Methods" (but they STILL don't acknowledge scent discrimination in the air scent dog ), and the "Cadaver Dog Handbook"

**Did you know that about 80% of the dust in a normal home is dead skin cells?

+++It is not quite as simple as the books make it look unless you live in the flatlands with no trees and a steady wind
- In our area the wind typically changes direction frequently and the mountains in the western part of the state do all kinds of neat things. But the basic concept is you work areas where scent is likely to go - depending on the time of day and weather and terrain - then if nothing is found you do a more detailed grid search .
 

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Ok one last thing I wanted to clarify in the water post was where I said they cannot pinpoint source.

By that I mean on land the dog can move its own body and nose to get as close to the scent source as doggedly possible.

In a boat they depend on us and letting them "steer the boat" helps us get right over it. But the boat is still moving, even if you kill the motor, so if the dog does a trained indication they may be past where the scent is coming out of the water before they finish. That is ok if you train a lot as you can figure it out but it is real definitive to see the dog snap its head and go to the back of the boat after you go over the scent.

Of course ponds and small lakes are one thing. Rivers and open water a whole 'nother thing altogether!!!!!!!!!!!! We recently did a water search on a sort of navigable river (if you count jumping out and pushing the boat in spots) and it was a lot harder to pinpoint because you really could not work a good patter.
 

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Some really good educational resources are "Scent and the scenting dog", "Ready" and "Training the k9 Hero, search and rescue dogs." Air scent dogs work off leash, they are either discriminating or non-discriminating. Discriminating air scent (also called area search dogs) are presented a scent article the same way a trailing dog is. They work off leash with the handler, usually working ahead of the handler and any flankers (searchers who go with the k9 and handler). The handler walks a zig zag grid covering the area (as terrain allows). If the dog finds scent of the subject they will usually leave the handler and can range a long way using their nose to close in on the subject. Once they pin point the subjects location they return to the handler and alert the handler that they have made the find. Lexi has a jump alert and will jump up on me to let me know. Then the dog leads the handler and flankers back to the subject. A non discriminating area search dog looks for human scent in the area and will alert the handler to any human they find. There are many variances on how this is trained and some handlers train the dog not to leave the subject but stay and bark to let the handler know the find has been made. I have never trained this method as I think (especially since I run gsd's) this would be very intimidating to the subject.
 

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The bark and hold is mainly used by disaster teams because of the danger of having a dog running on rubble back to the handler for a recall-refind. but a lot of other people have adopted it.

Down here, in our mountains, sound can be one place and sound like it is someplace else or with some of the hunters who may shoot a dog that comes up to them and starts barking at them. Not to mention a victim who may run.
 

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Discussion Starter #17
Wow, thanks.

As for the bark and hold, I have been on the receiving end so I can see how you would not want to use it in a search scenerio (I sometimes volunteer with the Police K9, they are trained to bark and hold when the subject stops. They apprehend only if you continue to run).

I also was aware there were currents under the water even in lakes (from my experience as a diver) so I was wondering how much that would affect the scent. Plus sometimes you get a different movement of water on top, then the wind. At least it would narrow an area down for divers to seach.

Thanks for all the info. I will be checking out the books. I have always been facsinated with K9 abilities to track but this has peaked it even more. I suppose it partly because I am part of the Underwater Recovery Team (I am one of the divers that would come out to get the body the dog found). Right now, we are the ones searching for cadavers in water.
 

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A general rule of thumb used on the ability to pinpoint is the radius of the area is the depth of the water - of course all the things you mentioned impact scent transport greatly and that rule is under *ideal* (HAH) conditions. You also need divers out of the water when working with dogs as the dogs will find the divers too****

***water searches are often within hours of death - and in cold water there may not be much decomp odor.

In 40 feet of water the body *should* be found within a circle of radius 40 feet from the alert(s)

We have found that is a pretty good estimate based on the few real finds we have had and training scenarios

You recovery divers amaze me !! --- . The thought of blindly working around the bottom of a lake feeling with your hands and bumping into a body ----- gives me shivers. I am somewhat familair with your techniques using either the ropes and either spiral or zig zag grid.

If you have a team to work with I would aks to come to one of their trainings and watch. A lot of dog teams use divers as part of the dog training and would welcome volunteers, but most of the training is done with scent generators (air pump, tubing, blows bubbles into water that are moderated to a low visibility - dog gets "proofed" off of bubbles not associated with scent) ----

You can PM me if you don't know of any and I can ask some of my contacts who is good in your area.

None of the books are really great on water cadaver. The cadaver dog handbook seems to have the most useful book information. I think the is the best I have seen ....go to the articles page

http://midatlanticdogs.org/


http://www.absarokasearchdogs.org/training/fielding_a_water_search_dog.php

They USED to have a lot of good articles on this but, oh well,
 

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A lot of dog teams use divers as part of the dog training and would welcome volunteers, but most of the training is done with scent generators (air pump, tubing, blows bubbles into water that are moderated to a low visibility - dog gets "proofed" off of bubbles not associated with scent) ----
*************************************************

I wanted to bring up something with regard to these "scent machines" I do not care for them. One must train the dog on an appreciable amount of HR. Scent machines cause the same problems as tiny amounts. This creates a dog whose threshold is too low to find a full set of remains. The dog will fringe and if the handler does not understand what is happening, divers will be put down a long way from point of origin,just like they do on land.

Also,my dogs are trained to alert at source. Period. I train this method in my seminars. My dogs work the entire boat. This makes it much easier for the operator to keep the boat "in odor". When the boat is over source, my dog alerts. My dog literally paws the water above the HR. I may or may not then cruise over it with side scan sonar and drop a camera, before putting a diver down.

I do not use divers either. It is not necessary to use a diver to train a water cadaver dog and it is just one more thing to proof the dog off of.


Also,the hold and bark for police work barely resembles the sport version. The dog must be moved farther away from the decoy and the dog must be proofed for movement. Crooks do NOT stay still when a dog is barking at them. Sport dogs are trained to engage if the decoy moves. Get you sued in the real world
 

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Renee, I fully understand what you say about fringing and working large source and realize it as a training problem to overcome when training with small scent sources. When we train with small sources we do not accept an alert in the fringe (and I have seen fringe alerts on relatively small stuff) but..............

We have not had real-life diffiucties with locating actual bodies during real searches using this method. Same thing with the hook right after we cross the source. If it works, what is wrong with it? What is wrong with reading and working with the natural behavior offered by the dog if it is consistent and you can articulate what it is? A lot of people use that technique. We do require a trained alert for land cadaver.

Also, some of that stuff in a scent machine can be so much scent that we can smell it on the surface..........I cannot smell a body underwater; usually those calls are pretty recent after the drowning........

We work full bodies with each cadaver dog every chance we get but, as you know, this is not the most common training experience. We always make the dog work to source. Short of that when we have the chance to, we like to combine our resources in one location on a large peice of land and work that way.

My own experience with my dog who had been trained on materials we can actually get, and a full body who was so badly decomposed in July that WE could smell it from about 300 feet was that I had to throw the ball to divert him before he launched on top of the body. No problem with going straight in. (Though I know some dog do hesitate when they get close but typically it has been within visual range)

We were talking about the hold and bark for wilderness dogs and intimidation factor - but I mentioned that it makes sense for disaster and if your dog does disaster and wilderness- those are the teams who normally seem to do that. I just prefer the recall-refind since I have a hard time locating a sound source in the mountains and it is far less intimidating.
 
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