Methodological Considerations in Canine Olfactory Detection Research

Abstract

Dogs are increasingly used in a wide range of detection tasks including explosives, narcotics, medical, and wildlife detection. Research on detection dog performance is important to understand olfactory capabilities, behavioral characteristics, improve training, expand deployment practices, and advance applied canine technologies. As such, it is important to understand the influence of specific variables on the quantification of detection dog performance such as test design, experimental controls, odor characteristics, and statistical analysis. Methods for testing canine scent detection vary influencing the outcome metrics of performance and the validity of results. Operators, management teams, policy makers, and law enforcement rely on scientific data to make decisions, design policies, and advance canine technologies. A lack of scientific information and standardized protocols in the detector dog industry adds difficulty and inaccuracies when making informed decisions about capability, vulnerability, and risk analysis. Therefore, the aim of this review is to highlight important methodological issues and expand on considerations for conducting scientifically valid detection dog research.

Investigation Police Dog Olfactory Acuity Through: Comparing Various Dog Breeds, Previous Training Experiences and Searching Site on the Detection of Narcotics

“…Canine cognitive and learning ability have an important role in scent detection performance besides their olfactory acuity (Lit, 2009;Lit and Crawford, 2006;Jezierski et al, 2008Jezierski et al, , 2010.…”

“…Olfactory acuity may be affected by genetic differences in olfactory receptors or anatomical variations in ear and nose shape. Bloodhounds have 300 million odor receptor cells, more than any other breed (Beebe et al, 2016;Lazarowski et al, 2020), and are considered to have the greatest olfactory acuity. Craven et al (2010) and Abney (2009), reviewed that mesocephalic breeds (i.e.…”

Training with Multiple Structurally Related Odorants Fails to Improve Generalization of Ammonium Nitrate Detection in Domesticated Dogs (Canis familiaris)

“…Therefore, it is possible that this disruption also affected any potential generalization that may have been observed. In our previous study, average baseline performance remained high, though some individuals did demonstrate reductions in performance for some of the tested odors, These results highlight the importance of including baseline trials as a comparison in order to accurately evaluate test performance [ 24 ]. Nevertheless, the current finding was surprising, given that we attempted to mitigate performance disruption by spreading the probe trials across several days, intermixed with reinforced baseline trials.…”

“…This system also has been used by others to evaluate cognitive function in dogs following aging, dietary manipulation, and pharmaceutical administration [ 19 , 20 , 21 , 22 ]. Laboratory-based studies of olfactory discrimination allow for a controlled analysis of olfactory learning and sensitivity in which a number of variables may be investigated including olfactory thresholds, rate of acquisition of learned response, and generalization to chemically related odors [ 9 , 23 , 24 ]. The present experiment relied on the use of a two-choice discrimination test apparatus and procedure for use with olfactory stimuli [ 15 ].…”

“…Nevertheless, the current finding was surprising, given that we attempted to mitigate performance disruption by spreading the probe trials across several days, intermixed with reinforced baseline trials. An alternative strategy would be to acclimate dogs to non-reinforced trials by introducing an intermittent reinforcement schedule during training to increase resistance to extinction [ 24 ], and to match training and test conditions as closely as possible. Another possibility is that the original training was not completely established, which could be addressed in future studies by requiring a lengthier criterion indicating the stability of performance.…”