Avalanche Dogs Can Locate 'Buried Victims' by Perceiving the Human Breath Under the Snow

Which components of the human scent steer dogs in finding a buried victim? The aim of this study was to evaluate if rescue dogs are able to locate a “buried victim” only by perceiving the human’s breath under a layer of snow in an avalanche simulate context, and which dog’s body postures are associated with a successful search. An operator blew for 18 minutes inside a tube buried under 1m of snow on a limited field (25m x 25m). After a 20-minute break, the SAGF (Alpine Rescue of [REMOVED]) Units (n=15) had to find the “buried victim”, i.e. the breath coming out from the hidden tube (15 minutes time-frame). When the SAGF dogs signalled the human breath and found the end part of the buried tube, the trial was considered successful. The protocol was replicated. SAGF-Units performed successfully most of the trials (26/30, 87%; P<0.0001) within a median latency time of 63s (IQR: 39-201s). Dog’s gender, age or breed and trial’s number did not affect success rate. During search, dogs spent most of the time (P<0.0001) with the head low (78%) and facing down (79%), neutral posture (91%), back parallel tail (50%), ears forward (74%) and closed mouth (64%). On successful trials, dogs spent more time with a high posture (P<0.001), head low (P<0.05) and facing down (P<0.01), vertical tail (P<0.01), and ears forward (P<0.05) compared with failed trials. In conclusion, human breath scent proved to be a valuable indicator to locate a “buried victim” for avalanche dogs.