DOG NOSE BEST Can cadaver dogs be used as an effective tool for recovering human remains? Introduction 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. Questions 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? Hypothesis Cadaver dogs are an effective tool in detecting human remains if trained properly using cadaverine and putrescine. Breed Selection German Shepard (Gs), Rotweiler (R), Bloodhound (Bh) Gs (N=10 ) R (N=10) Bh (N=10) Odor Sensitivity Laboratory Training Cadaverine/Putrescine- Exposed for 10 min, 3 times daily, for 1 month Field Trials (Table 1) Temp: C Depth Buried: cm Odor Recognition Success Analysis (ANOVA and paired t-test) 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). Materials and Methods Table 1: Description of field trials exhibited by all three breeds of dogs to aid in the ability to determine their effectiveness. Example of Expected Results Literature Cited Graubart, N. My Dog. Rosen Publishing Group, New York, NY Haglund, William (1996). Forensic taphonomy: The Postmortem Fate of Human Remains. CRC Press. p Hussain, A. High affinity olfactory receptor for the death associated odor cadaverine. PNAS New York, NY Komar, D. The use of cadaver dogs in locating scattered, scavenged human remains: preliminary field test results. J Forensic Sci 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 May;48(3): 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) : 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): 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) 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. Brittany Hicks, York College Department of Biological Sciences Figure 1. example of field trials showing a 60% recovery for 5 buried remains with one false positive detected. Pre-Training Field Trial: no introduction to chemicals TrialsSamples Used 1Fresh skeletal remains 2Dry skeletal remains 3Stage 1 decomposition 4Stage 2 decomposition 5Stage 3 decomposition 6Stage 4 decomposition 7Stage 5 decomposition