Dogs have a much more powerful sense of smell than humans, being able to detect odours from drugs, underground gas leaks, buried dead bodies, currency, explosives, mines and even human illnesses. Scientists have conducted experiments where dogs can sniff out the start of epilepsy and diabetes.
No hiding place
I watched a programme on TV the other night where they experimented with a banned substance to see if the dog could detect it if it were disguised with some other, pungent smell. They put a small bag of the substance inside a large tin of ground coffee, sealed the lid and hid it in a warehouse containing 30,000 stage props. There were aisles of the props stacked ceiling high with all kinds of things. The dog took about 40 seconds to find the drugs in the tin of coffee. Then they tried peanut butter. They sank the envelope of drugs in the tin of peanut butter, sealed it and hid it. They used a different dog and he found it easily. In an Australian jail a detection dog foiled an attempt to smuggle in drugs that had been hidden in a woman's bra and smeared with pepper, coffee and evil smelling vapour rub.
So how are dogs better at detecting odours than us humans? A large part of the doggie brain is employed to analyse odours. They have two large areas of the brain which are used to decode every smell they happen to come across. These areas are four times as sensitive as the human brain's area. As the doggie brain is very much smaller than the human one it means that the sense of smell is up to a million times more sensitive than ours.
The dog uses it's wet snout to detect a smell. The wet surface traps the tiniest hint of smells, which are passed on to it's internal receiving cells which then analyse them and he is able to select the one he wants. This is why the dog has a constant wet nose, producing an enormous amount of mucus every day.
Some people think that the dog has to be addicted to a drug to detect it but this is not the case. The dog is trained to associate it's favourite toy with the drug and is really searching for the toy. This is why the dog handler always rewards his detection dog by producing the toy and encouraging the dog to play.
My father-in-law had a theory that dogs could talk, but they wouldn't because if they did, we would get them working. Well, dogs love to work without the need for talking.