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DOG NOSE BEST
Can cadaver dogs be used as an effective tool for recovering human remains?
Brittany Hicks, York College Department of Biological
Sciences
Questions
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Introduction
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Canines have an olfactory cortex 40 times larger than humans
which gives them a sense of smell 100 million times as sensitive.
This unique olfactory system allows canines a high degree of
discrimination that when trained correctly can be used as a
powerful detection tool.
Dogs can be trained to detect human remains after death and
distinguish between remains and stages of decomposition.
Polyamines, cadaverine and putrescine , serve as biomarkers for
human decomposition and are used to train dogs in locating
decaying human remains.
Previous studies have shown that dogs, if trained properly, can
be effective tools in tracking, searching, and locating evidence.
The purpose of this study is to determine whether training
cadaver dogs with the use of cadaverine and putrescine in a
laboratory setting is an efficient tool for law enforcement.
Review of Literature
• Cadaver dogs showed a 81% recovery in a double blind experiment
in which dry human bone, animal bone, gauze soaked in human
decomposition fluids and clothing soaked in decaying fluids were
used. The rate of recovery decreased when using dry human
bones (Komar, 1999).
• Human decaying process occurs over five stages beginning with
fresh decomposition, progressing through early and advanced
decomposition to skeletonization and finally to extreme
decomposition. Results show dogs had the ability to narrow down
search area and located skeletonized remains (Lasseter et. al.,
2003).
• Cadaverine and putrescine are produced by the breakdown of
amino acids in living and dead organisms (Haglund, 1996).
• The two diamines emanating from decaying flesh have a strong
repulsive odor recognizable for detection.(Hussain et. al., 2013)
• Decarboxylation of amino acids, cadaverine and putrescine are
present in all decaying organic material of individuals. Results
indicated excellent sensitivity, specificity and accuracy by cadaver
dogs when identifying human remains. (Oesterherlweg et. al.)
• A comprehensive carpet square study shows that accuracy of scent
detection and precision by the dog may be acting correctly to the
scent of decomposed tissue unsure of differentiating where the
scent is being released (Zanoni, 1998).
• The use of dogs to locate human remains is popular because they
show accuracy, are relatively inexpensive, and provide a thorough
and quick search for a large area functioning in both day and night
(Lorenzo et. al., 2003).
• Mammalian neurons are activated by low concentrations of
cadaverine expressed by a particular olfactory receptor, trace
amine-associated receptors (TAAR) (Hussain et al., 2013 & Zhang
et al., 2013).
• In tests, dogs have been able to detect chemical solutions diluted
to 1 to 2 parts per trillion. The Bloodhound has over 300 million
smell receptors. (Graubart, 2014).
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Do breeds of dogs and their training experience affect
success of recovering human remains?
Is a laboratory setting an efficient place to train the dogs
so that they will be able to detect the original scent of
decaying remains using relevant volatile chemicals?
Can dogs detect a significant amount of human remains if
trained with cadaverine and putrescine to be used in law
enforcement?
Figure 1. example of field trials showing a 60% recovery for 5 buried
remains with one false positive detected.
Hypothesis
Cadaver dogs are an effective tool in detecting human
remains if trained properly using cadaverine and
putrescine.
Table 1: Description of field trials exhibited by all three breeds of dogs to aid in
the ability to determine their effectiveness.
Materials and Methods
Trials
Samples Used
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Fresh skeletal remains
Dry skeletal remains
Stage 1 decomposition
Stage 2 decomposition
Stage 3 decomposition
Stage 4 decomposition
Stage 5 decomposition
Breed Selection
German Shepard (Gs), Rotweiler (R), Bloodhound (Bh)
Example of Expected Results
Gs (N=10)
R (N=10)
Bh (N=10)
Pre-Training Field Trial: no introduction to
chemicals
Odor Sensitivity Laboratory Training
Cadaverine/Putrescine- Exposed for 10 min, 3
times daily, for 1 month
Figure 2. Expected results of the various breeds in which positive flagging was recorded
for comparison through percent recovery for the seven field trials. (refer to table 1)
Literature Cited
Field Trials (Table 1)
Temp: 10-18 C
Depth Buried: 30- 45 cm
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Odor Recognition Success Analysis
(ANOVA and paired t-test)
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Graubart, N. My Dog. Rosen Publishing Group, New York, NY. 2014.
Haglund, William (1996). Forensic taphonomy: The Postmortem Fate of Human Remains. CRC Press. p. 100.
Hussain, A. High affinity olfactory receptor for the death associated odor cadaverine. PNAS New York, NY.
2013.
Komar, D. The use of cadaver dogs in locating scattered, scavenged human remains: preliminary field test
results. J Forensic Sci. 1999 Mar;44(2):405
Lasseter AE., Jacobi, KP., Farley, R., Hensel, L..Cadaver dog and handler team capabilities in the recovery of
buried human remains in the southeastern United States. J Forensic Sci. 2003 May;48(3):617-21.
Lorenzo, N., Wan, T., Harper, R., Hsu, Y., Chow, M., Rose., Furton, K. Laboratory and field experiments used
to identify Canis lupus var. familiaris active odor signature chemicals from drugs, explosives, and humans.
Analytical and Bioanalytical Chemistry. 2003; 376 (8) : 1212-1224.
Oesterhelweg L,., Krober, S., Rottman, K., Willhoft, J., Braun, C., Theis, N., Puschel, K., Silkenath, J., Gehl, A.
Cadaver dogs–a study on detection of contaminated carpet squares. Institute of Legal Medicine, University
Medical Center Hamburg, Germany.
Zanoni, M., Morris, A., Messer, M., Martinez, R. “Forensic Evidence Canines: Status, Training, and
Utilization.” American Academy of Forensic Sciences. (1998)
Zhang , J., Pacifico, R., Cawley, D., feinsteiin, P., Bozza, T. Ultrasensitive detection of amines by a trace
amine-associated receptor. J. Neurosci. 2013; 33(7): 3228-3239.
Acknowledgements
I would like to thank Dr. Rehnberg, who provided mentorship and guidance throughout this research
experience. I’d also like to thank Dr. Kleiner for his help and critiques and all of my friends who assisted me
in developing research.