1 National Urban Search & Rescue Response System Canine Search Specialist Training Canine Search Specialist Training Unit 5: Scent Theory

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National Urban Search & Rescue Response System

Canine Search Specialist Training


Unit 5:

Scent Theory

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Unit Objective

Upon completion of this unit, you will be able to explain the theory of scent as it relates to the canine search for live victims in a collapsed structure

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Enabling Objectives

Explain the rationale for understanding scent movement

Describe the factors that may affect scent

Describe how scent is transported away from the victim

Plan the search of a collapsed structure to efficiently work canines into scent

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Rationale

Dogs “see” the world through their noseScent is 3-dimensional to themOur job is to put them where they can

best detect scent

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The Canine Olfactory System

The Nose Knows

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Canine Olfactory System

Olfactory sensory cell estimates

Human = 5 million

Canine = 220 million

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Canine Search Specialist Training CONTRIBUTORS TO HUMAN SCENT COMPLEX

Human Scent SebaceousSebaceous

Sebum, Squalene

Respiratory TractGI Tract

Volatile Fatty AcidsAmines

BacterialAction

K, Cl, Urea, CaMg, PO4, HOH

MEOHH2SO4

Volatile Fatty Acids

ApocrineApocrine

EccrineEccrine

Other factors: Genetic, Diet, Environment

Adipose

Huh?

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What is scent to a canine?

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The Raft Theory

Dying/dead, bacteria laden skin cells—called rafts

Rafts are shed fromSkin Respiratory and digestive tracks

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Skin raft loss

Approximately

40,000 per minute!

“If one gram of butyric acid was made to evaporate evenly in all the rooms of a ten story office building, a man would barely be able to perceive its existence by standing in one of the rooms. However, if the same gram of butyric acid was diluted to fill the air above the entire city of Hamburg, the dog could still perceive it at an altitude of 300 feet.”

William SyrotuckScent and the Scenting Dog, pg. 13

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How is scent dispersed?

The scent is heaviest at the source and dispersed away from the victim in a cone

Scent Dispersal

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Influences on Scent Dispersal

Environmental Influences

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Environmental Influences

Temperature Wind strength and

direction Humidity Sun

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Temperature

HotColdThe temperature of victim versus the

temperature of the environment

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Wind

StrengthDirection

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Humidity

HighLowRain

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Sun

ClearOvercast Night

Night-time Flows

Day-time Patterns

Structural Influences

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Structural Influences

Building architectureElevator shaftsClosed stairwellsWindowsBreached floors/walls

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Structural Influences (continued)

Scent flows well inBroken rubbleLight framingBrick

Katrina 2005

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Scent Flow and Detection

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Scent Flow and Detection

The disaster search canine is trained to indicate the presence of a live victim by performing a focused bark alert at the point in the rubble where the strongest live human scent is emitted Bark!

Bark!

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DETECTION versus LOCATION

Dogs are SCENT detectors NOT victim locators!

Scent Flow—Channeling

scent conescent cone

scent cone

BARK

• Solid Slabs

• Large Chunks

• Solid Slabs

• Large ChunksBARK BARK

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Scent Source Detection

Be able to interpret your dog’s alertDocumentDebrief

Handler to STMHandler to Handler

Scent Flow—Funneling

Bark! Bark!Bark! Bark!

Scent Flow—Pooling

Bark! Bark!Bark! Bark!

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Typical Collapse Patterns

Lean-To“V”PancakeCantilever

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Lean-To

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“V”

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Pancake

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Cantilever

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What is this?

Ho

t W

all

Co

ld W

all

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Use your scent knowledge

Identify scenting conditionsSurveyor’s tape, puff bottles/talc mirror

scent pattern

Interpret pattern of alertsSend canine from position which

maximizes probability of detection

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Considerations

Hazardous materialsLive versus deadNumber of victims foundDistractions

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Questions?

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Scent Theory/Air Movement Demonstration

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Unit Summary and Evaluation

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Unit Summary

Explain the rationale for understanding scent movement

Describe the factors that may affect scent

Describe how scent is transported away from the victim

Plan the search of a collapsed structure to efficiently work canines into scent

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Unit Evaluation

Please fill out the evaluation on this briefing

Documents

1 National Urban Search & Rescue Response System Canine Search Specialist Training Canine Search Specialist Training Unit 5: Scent Theory