Search Dog Handbook - Scott County Search and Rescue K9 Unit

SEARCH DOG HANDBOOK
This type of dog has the highest discriminatory potential as he must
constantly discriminate the cue odor from the surrounding environment
and then determine its point of strongest concentration.
Their one limitation is that they are not particularly ground oriented for
precise tracking, but they can and do trail when this has been included
as part of their training.
Scent
All those combinations of odors or smells that characterize an individual.
The main ingredients of human scent are the bacteria acting upon the
dead cells in the environment of the skin secretions. Bacteria break down
the cell components and secretions, such as protein, into amino acids.
The amino acids, in turn, are broken down into such chemicals as
ammonia, methane and hydrogen sulfide.
The resultant by-products have characteristic odors that are probably a
mixture of vapours and gases. Such bacterial action is a fundamental of
scent. Raft, carrying bacteria and body secretions enshrouded by the
resultant vapour make up scent.
Discrimination
The dog does not recognize the scent of an individual because of the
presence of some one, single chemical substance peculiar to that person,
but rather because of a pattern or complex to which substances may
contribute even if they are present in sub-threshold amounts (Neuhaus).
This scent pattern becomes the scent “fingerprint” unique to each person
by which dogs discriminate among different people.
Scent Plumes (also see 77 Facts #28)
Typical Sequence:
Night - clear calm fanning
Sunrise + 1/2 hour fumigating
Daytime looping
Sundown lofting
Odor
Specific: chemical, axilla (odor), foot (odor), etc.
Page 15