A lot of research depends upon making comparisons between healthy and sick individuals. And the results of these comparisons have been used to develop newer and better diagnostics, prophylactics and treatments. The current study is also pretty much based on comparison between ducks that are infected with the Bird Flu virus and those that were completely healthy. The only difference here being that the comparison involved the smell of the feaces of the two groups of ducks in question, and the ‘detectors’ of these olfactory differences were lab-trained mice!

Yes! You read that right. An unusual proof-of-concept experiment was carried out by researchers at the U.S. Department of Agriculture led by scientist Bruce A. Kimball, Ph.D. the results of these experiments were presented today at the 240th National Meeting of the American Chemical Society (ACS). This study was a part of about 8000 scientific reports to be presented at the meet, making it easily one of the largest such conventions in 2010. The ACS is a non-profit organization chartered by the US Congress.

Dr. Kimball

Dr. Kimbal, USDA

“Based on our results, we believe dogs, as well as mice, could be trained to identify a variety of diseases and health conditions,” said U.S. Department of Agriculture scientist Bruce A. Kimball, Ph.D., who presented the study results. “In fact, we envision two broad, real-world applications of our findings,” Kimball added. “First, we anticipate use of trained disease-detector dogs to screen feces, soil, or other environmental samples to provide us with an early warning about the emergence and spread of flu viruses. Second, we can identify the specific odor molecules that mice are sensing and develop laboratory instruments and in-the-field detectors to detect them.”

Dr. Kimball speculated that a “suite of chemicals, rather than a single compound” might responsible for the difference in fecal odor between healthy and infected ducks. The team is now investigating instrumentation methods to detect these volatile chemicals. Once this has been accomplished, statistical and pattern analysis could reveal the presence of an infection.

The experiment used the classical reward when correct method that has been time-honored in animal studies. In-bred mice were allowed to navigate a maze and when they identified feces of an infected duck, they were rewarded with a Drink of water! Needless to say there were no rewards for picking out the excrement of a healthy duck. Eventually, the mice were trained to spot the infected feces. This method could be extrapolated to train dogs in a similar fashion. SOURCE

Bird flu viruses carried by migratory birds can be spread far and wide, even across continents. Given the close proximity of human and bird populations (wild or domesticated) in many countries including India, an inter-species jump by the virus could result in serious infections in humans, some even being fatal. The prospect of simply using trained sniffer dogs to sniff out the soil near large bird farms might serve to detect the emergence of bird flu and to put in place systems to prevent an epidemic of the human or avian kind.

Well, this does not really seem so outrageous in the light of earlier research involving dogs and cancers. Dogs have been shown to be able to sniff out cancers like melanoma and bladder cancers. Here again certain volatile benzene derivatives present in the breath of cancer patients seem to be the indicator molecules. So researchers at the Pine Street Foundation in San Anselmo, California, US, selected three Labrador retrievers and two Portuguese water dogs with no previous training, and over several weeks trained them using breath samples that had been exhaled into tubes by cancer patients.

To test how well the dogs had learned, they used a new batch of samples and had the dogs attempt to distinguish among 55 lung cancer patients, 31 breast cancer patients and 83 healthy controls. The patients had all had their cancers confirmed by biopsy. The tests were double-blind, so neither the dog handlers nor the experimenters knew which tubes were which. (Integrative Cancer Therapies : vol 5, p 1).

James C Walker, director of the Florida State University Sensory Research Institute in Tallahassee, US, In 2004 showed that dogs could sniff out melanomas. He says that the next step is to see if dogs are really detecting cancer, or if they might be sensing a more general disease symptom, such as one that comes from inflammation. Walker says he would like, eventually, to see a long, large-scale trial designed to test whether dogs can detect cancer even earlier than standard screening tests.

The development of dogs as “biosensors” of the olfactory type will be a tremendously useful technology on the ground for early detection of diseases such as cancers or virus infections. One way or the other, these animals will be able to prevent mortality and will be instrumental in saving lives of people and other animals as the case may be.

The researchers across the world in different study centers need to be applauded for their brilliant and simple deductions in using animals, specifically dogs for detecting illness. We hope that this research can soon be brought to the fields and will be instrumental in saving lives and preventing epidemics or even pandemics like the Avian Flu or the Swine flu pandemics that are so fresh in our minds. SOURCE

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