In class today John spoke about how Giant African Pouched Rats could sniff out landmines as well as tuberculosis (Tuberculosis Rat paper if you're curious). Well it turns out a large number of other animals also show potential for sniffing out disease - including dogs. This study looked at detection of human bladder cancer by having trained dogs sniff human urine and found a mean success rate of about 55%. While that number isn't significant on its own (the dogs still miss quite a lot of cases), it does show that dogs have the ability to smell it and shows a lot of potential for training dogs for this purpose in the future. Could we train a dog to have an 80% success rate? or even 95%? This study looked at dogs as well but in testing for lung cancer on the patients breath. They managed to get even better results with an overall sensitivity (or successful diagnosis) of 71% and a specificity (or successfully saying the person does not have cancer) of 93%. These numbers are pretty high and show just how much potential canines have in determining disease.
Beyond just dogs and rats, a number of other animals and methods have started to be investigated for the purpose of testing for things. Fruit flys have been tested to look for cancer, mice for bird flu in birds, bees for explosives at airports, pigeons for breast cancer and much more. A cool specific example - a company called Inscentinel has developed a handhold device that holds 36 bees inside that uses a vacuum to draw air over the bees from a potential explosive and then the user can see on a screen how many bees "said yes" (and by "said yes" I mean extended their proboscis) allowing for an easier method of explosive detection. Animals are pretty cool!