Section of Clinical Biochemistry, Department of Neuroscience, Biomedicine and Movement, University Hospital of Verona, Piazzale L.A. Scuro, 10, 37134 Verona, Italy.
School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
Clin Chem Lab Med. 2020 Jun 25;58(6):958-967. doi: 10.1515/cclm-2019-1269.
A sniffer (detecting) dog is conventionally defined as an animal trained to use its olfactory perceptions for detecting a vast array of substances, mostly volatile organic compounds (VOCs), including those exceptionally or exclusively generated in humans bearing specific pathologies. Such an extraordinary sniffing performance translates into the capability of detecting compounds close to the femtomolar level, with performance comparable to that of current mass spectrometry-based laboratory applications. Not only can dogs accurately detect "abnormal volatilomes" reflecting something wrong happening to their owners, but they can also perceive visual, vocal and behavioral signals, which altogether would contribute to raise their alertness. Although it seems reasonable to conclude that sniffer dogs could never be considered absolutely "diagnostic" for a given disorder, several lines of evidence attest that they may serve as efficient screening aids for many pathological conditions affecting their human companions. Favorable results have been obtained in trials on cancers, diabetes, seizures, narcolepsy and migraine, whilst interesting evidence is also emerging on the capability of early and accurately identifying patients with infectious diseases. This would lead the way to proposing an "olfactory fingerprint" loop, where evidence that dogs can identify the presence of human pathologies provides implicit proof of the existence of disease-specific volatilomes, which can be studied for developing laboratory techniques. Contextually, the evidence that specific pathologies are associated with abnormal VOC generation may serve as reliable basis for training dogs to detect these compounds, even (or especially) in patients at an asymptomatic phase.
嗅探犬通常被定义为经过训练，能够利用嗅觉感知来检测各种物质的动物，主要是挥发性有机化合物（VOC），包括那些在患有特定疾病的人类中异常或专门产生的物质。这种非凡的嗅觉表现转化为能够检测接近飞摩尔级别的化合物的能力，其性能可与基于当前质谱的实验室应用相媲美。嗅探犬不仅能够准确地检测到反映主人异常情况的“异常挥发组”，还能够感知视觉、声音和行为信号，这些都有助于提高它们的警觉性。虽然似乎可以合理地得出结论，即嗅探犬永远不能被视为特定疾病的绝对“诊断”工具，但有几条证据表明，它们可以作为许多影响其人类伴侣的病理状况的有效筛选辅助工具。在癌症、糖尿病、癫痫、发作性睡病和偏头痛的试验中取得了有利的结果，而在早期和准确识别传染病患者的能力方面也出现了有趣的证据。这将为提出一个“嗅觉指纹”循环铺平道路，即狗能够识别人类疾病存在的证据为疾病特异性挥发组的存在提供了隐含的证明，这可以为开发实验室技术提供研究基础。相应地，特定疾病与异常 VOC 生成相关的证据可以作为训练狗检测这些化合物的可靠依据，即使（或特别是）在无症状阶段的患者中。
