DOCTORS ' LOUNGE
DOCTORS ' LOUNGE
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THE SCHNOZ THAT COULD AUTHOR Mary Barry , MD
Ever since I ’ d read some years ago about dogs who can smell diseases , I ’ ve gotten curiouser and curiouser . Over Derby , I was lucky to meet the wondrous 2-year-old Riley , a small , serious , darling black Doodle who can detect drops and highs in his owner ’ s blood sugar , and warn her 15 minutes before her DexCom does . He learned how by smelling different concentrations of glucose in saliva samples and then in particular , her saliva samples . He ’ d first had to pass Basic Obedience , then Therapy Dog training . Then he ’ d learned to smell the difference and to perform an immediate Alert for abnormal sugar levels in saliva samples . Finally , he ’ d been trained using his owner ’ s own saliva samples . He ’ d be lying quietly and correctly under the table and then wham ! he ’ d be up , sniffing everyone and then pawing her knee commandingly . He ’ s awakened her in the wee hours even though he ’ d been asleep too : the survival instinct is tied very tightly to smell , in dogs . Under perfect conditions of wind and weather , dogs have been reported to smell their owners close to 20 km away . Dogs can detect the most miniscule of trace scents : one part per trillion . He ’ s a lifesaver of a dog and he loves to play Keep Away . He can melt your heart in seconds .
Researchers have been hard at work here and internationally , trying to export , then replicate , the exquisite sensitivity and discrimination of the canine nose to various artificial neural networks ( ANN ). Dogs have reportedly sniffed out melanoma and basal cell skin cancer . They have detected breast cancer and lung cancer by smelling the breath of patients vs . controls . They have repeatedly sniffed their owners ’ chests in an odd manner , enough to convince the owners to seek a diagnosis . They ’ ve been found to differentiate the urine of control specimens vs . the urine of bladder cancer patients . They have identified colorectal cancers by smelling control vs . patient stool samples , as well as the patients ’ breath . They have identified positive biopsy samples of cervical cancers vs . negative ones . The trick is to translate this skill from one dog to a replicable , standardized olfactory test .
In 2015 ( Journal of Urology 1 April 2015 ) Taverna et al tested 362 known prostate cases ’ urine samples against those of 540 male GU clinic attendees , using two female 3-year-old German Shepherd explosives-detecting dogs . One dog proved to have 100 % sensitivity and the other dog , 98 %. This really got the scientific ball rolling ( reference https :// doi . org / 10.1016 / j . juro . 2014.09.099 ).
Dr . Claire Guest founded a British charity , Medical Detection Dogs , after her own dog had repeatedly and worrisomely pawed her chest , until she paid attention and got a breast cancer diagnosis in return . Her group has been training them in all manner of bio-sensing compounds ever since . US based researchers working with her dogs have back in February published their recent success in the cross-fertilization of canine and artificial intelligence skills for the detection of prostate cancer rated as Gleason score 9 . They used two dogs smelling urine samples from men undergoing prostate biopsy , to develop a protocol for finding volatile organic compounds analyzed by gas chromatography and mass spectroscopy ( GC-MS data ). The urine compound data were analyzed by the AI network . They also used urine microbial DNA as an additional marker to see if biopsy-positive urinary bugs differed from biopsy-negative ones . This was a double blinded NIH-funded pilot study with multiple co-author collaborators , led by the Department of Urology at Johns Hopkins . It was published in the open-access journal out of San Francisco , PLOS ONE , 2 17 21 : ( https :// doi . org / 10.1371 / journal . pone . 0245530 ). ( continued on page 30 ) JUNE 2021 29