ABSTRACT
As discussed in Chapter 3, the human skin is a rich source of volatile production that has allowed the chemical elucidation of dierent compounds through an array of analytical techniques. In turn, these techniques have allowed for a number of studies to focus on the detection of specic volatiles that represent the odor of patients suering dierent diseases. As the generation of human odor is directly linked to metabolic processes, the volatiles detected are a good reection of internal health conditions. Sources for volatile identication have included samples from breath, blood, skin, and urine.1 ese disease specic volatiles can then be directly applied as diagnostic tools (i.e., olfactory biomarkers) essential in therapeutic processes.2-4
Canines have been implemented for disease detection in the last decade due to their extraordinary sense of smell oering sensitive detection abilities. In cases of cancer, canines have been trained to discriminate odor samples
from healthy and diseased individuals using urine, breath, and even watery stool as scent sources. Odors associated with lung,5,6 breast,7 bladder,8 prostate,9 and colorectal10 cancer have been used to exploit dog as biological detector system. Results have shown promising results yielding sensitivity greater than 70% as well as high specicity rates within the sampled populations. ese studies have shown that canines could be trained to distinguish patients on the basis of the odor signatures emitted by the dierent specimens more successfully than would be expected by mere chance. Canines have also been implemented to detect hypoglycaemia in diabetic patients, proving to be successful alarm systems to changes in glucose concentrations by notable changes in behavior.11 Other studies have even evaluated canines for the detection of seizures, with ndings suggesting that some dogs have innate ability to alert and/ or respond to epileptic patients.12 Even though the exact mechanisms by which dogs detect these changes is still largely unknown, the usefulness and potential for disease detection has been clearly demonstrated and is thus an area of current research eorts by scientists worldwide.
