Numerous roles for the domestic dog (Canis familiaris) have existed for thousands of years. The role of bio-detection, dogs discriminating between biological odours, is a recent and rapidly ...developing area. Research within the field has previously concentrated on dogs' ability to detect odours associated with human disease states and health conditions. However, processes outside of disease, such as human emotions, also produce measurable changes in physiological and biological markers. This thesis has an application to human stress, which is a leading cause of mental and physical health disorders, and a sensation that many people feel on a daily basis. If dogs can smell changes within the human body caused by disease, might they also be able to smell stress? The bio-detection paradigm allows for exploration into these areas by testing the scope of dogs' abilities to discriminate between human odours. Results of this thesis provide evidence supporting the premise that the human stress response produces a change in odour that is detectable by dogs, with each study chapter highlighting areas of consideration, including the nature of this relationship outside of the laboratory setting, the practical limitations of bio-detection paradigms, and whether a popular protocol used to measure affective state in dogs should be used in repeated measure designs. The final chapter provides a general discussion, which considers the implications of these study findings, discusses future directions of this work, and establishes how the methodologies developed and critiqued in this thesis may inform future research in this field.
Human remains detection dogs (HRDD) are commonly used by law enforcement agencies to search for cadavers. Biological material is typically used as a training stimulus, also called aids, to train dogs ...to recognize the smell of cadavers. While HRDD training approaches have received extensive attention, information remains limited on the olfactory cues used to train them. Here, we aimed to decipher the chemical basis of detection dog olfaction. Five specific objectives were explored to precise whether the composition or the concentration of the training aids drives the HRDDs responses. We recorded the behavioral responses of four HRDDs exposed to different cadaveric‐like smells. We found that HRDDs recognized a simplified synthetic aid composed of cadaveric compounds. The lowest concentration at which HRDDs continued to perceive the cadaveric smell was determined. HRDDs were not impacted by slight modifications to the chemical composition of a blend of odors that they have been trained with. HRDDs associated sulfur and nitrogen compounds as human cadaver. Our findings highlight a lack of specificity of HRDDs to cadaveric compounds, which could lead to error of detection. Moreover, all dogs did not positively respond to the same blends, despite being trained with the same aids and procedure. However, we confirmed that dogs could be trained with a simplified blend of molecules. The chemical composition of a training aid has, therefore, high consequences on the performance of the trained animal, and this conclusion opens additional questions regarding olfaction‐based detection animals.
The twenty-first century pet domestic dog typically spends a large amount of time in the home environment. An audio/food dispensing automated device (an artificial agent, hereafter agent) was ...evaluated for enrichment potential. The agent issued verbal cuesto dogs and puppies, and food rewards for their correct behavioural responses. Dogs' and puppies' abilities to respond correctly to the cues and their welfare during interaction was measured. Three empirical studies are presented. Key findings of the cognitive tests (study one) include: 1. no significant difference in dogs' correct behavioural responses to the agent's cues between initial exposure and following a 24-month break (p = 0.119); 2. no significant difference in correct 1st choice behavioural responses to multiple, randomised cues issued by the agent and by owners directly (p = 0.526); 3. significantly longer response latencies to cuesin agent conditions vs owner condition (p = 0.026). Dogs were able to learn a novel sequence of known behaviours from the agent during a single testing session. Study two measured dogs' welfare during the cognitive tests described using Qualitative Behavioural Assessment (QBA) and quantitative behaviour sampling. QBA PC1 characterised dogs as ranging from 'attentive/interested/anticipating' to 'conflicted/apathetic' in each experimental testing condition with the majority of dogs at the former end of the PC. Inter-observer agreement was high on all PCs (average Kendall's W = 0.82). No significant differences in quantitative positive state behaviours between conditions were found (average p = 0.595); these behaviours correlated significantly with QBA PC1 in all conditions(average r = 0.791). The study represents the first application of QBA to a cognitive paradigm and suggests that positive reinforcement interaction with an owner or with an agent may promote an experience of pleasure in dogs. Study three examined puppies' responses to randomised verbal cues issued by the agent and by owners directly for comparison. Attentional focus on the agent was rapidly achieved (average 18.8 sec from start of introduction to agent). No significant difference in puppies' correct 1st choice behavioural responses to cues issued by the agent vs owners was found (p = 0.609); significantly longer response latencies to cues in the agent vs owner condition were revealed (p = 0.001). Overall, indicators of positive anticipation, motivation, competence and sustained engagement were identified in the majority of dogs and puppies throughout testing, suggesting that agent-interaction represents an appropriate cognitive challenge. Puppy owners reported overarchingly positive opinions of their puppies' interactive experiences; the majority supporting the trial of an agent in the home.
As part of an evaluation of Dutch breed specific legislation, data were collected from dog bite victims (1078) and dog owners (6139) using Internet surveys. The incidence rate of dog bites and ...details of incidents (victims, injuries, circumstances and aggressors) are reported and the justification for using breed specific measurements to deal with dog bites are considered. For aggressors, attack records for breed groups and popular breeds were established by calculating breed risk indices using a reference population. Several breeds and breed groups were over- and under-represented in the biting population and there was a mismatch between risk indices and the then-current legislation. Mitigation strategies should not be based on attack records (since this would lead to the rejection of a significant proportion of the canine population) but on the circumstances of the incidents. Preventative measures must focus on a better understanding of how to handle dogs.
The present study addresses the lack of research on Staphylococcus spp. among dogs in South Africa. The study characterises isolates from retrospective data from a veterinary diagnostic laboratory in ...terms of time, place, and animal factors. Using data collected from 2012 to 2017, the study analysed 1627 positive Staphylococcus isolates and identified 10 species, the majority (92.0%) of which were classified as coagulase-positive, while a few were coagulase-negative (6.0%) and coagulase-variable (3.0%). Male dogs contributed just over half (53.2%) of the isolates. Dogs aged ≥9 years contributed the most isolates (23.2%). KwaZulu-Natal Province contributed the majority (45.0%) of the isolates, while Northern Cape Province contributed the least (0.1%). Almost half (46.0%) of the isolates came from skin specimens. The study demonstrated a limited variation in the number of Staphylococcus isolates across seasons and the occurrence of a diversity of Staphylococcus species among dogs in South Africa. There is a need for research to improve our understanding of factors that influence the observed disparities in Staphylococcus spp. Proportions observed in this study. There is a scarcity of published studies on the occurrence of Staphylococcus spp. Among dogs in South Africa. The objective of the study was to characterise the Staphylococcus spp. Isolated from dog samples submitted to a veterinary diagnostic laboratory in South Africa in terms of time, place, and person. This study utilised a dataset of 1627 positive Staphylococcus isolates obtained from a veterinary diagnostic laboratory in South Africa from 2012 to 2017. Out of the 1627 confirmed isolates, 10 different species of Staphylococcus were identified. Among these, 92.0% were classified as coagulase-positive staphylococci (CoPS), 6.0% were coagulase-negative staphylococci (CoNS), and 3.0% were coagulase-variable. Male dogs contributed just over half (53.2%) of the Staphylococcus isolates, while female dogs contributed the remaining 46.8%. The largest proportion of isolates (23.2%) were obtained from dogs aged ≥ 9 years, with the highest number of isolates originating from KwaZulu-Natal Province (45.0%) and the least from Northern Cape Province (0.1%). Out of the total samples included in the records, the majority (46.0%) were skin specimens. The number of Staphylococcus isolates recorded showed limited variation between the seasons (24.3% in autumn, 26.3% in winter, 26.0% in spring, and 24.0% in summer). This study highlighted the diversity of Staphylococcus spp. isolated from dogs, and the burden of staphylococcal carriage among dogs in South Africa. Further research is required to examine the factors that contribute to the observed discrepancies in the proportions of Staphylococcus spp. between the provinces.
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