The smelling receiver is made up of a mucous, a labyrinth of innumerable folds that could cover a surface of 130 m2 compared to the 3 m2 that humans have. The dog has 120 to 220 million cells next to man's 5 million cells. Its smell is so developed that it can detect the lightest environmental change.

As a matter of fact, the dog can detect the change of character of other dogs or humans that surround them, just by detecting the slight increase or decrease of their hormonal levels and their sweat. This has nothing to do with a sixth sense: the dog can just detect certain signals that go unnoticed by humans.

There have been anecdotal reports that 'man's best friend' can spot cancer in their owners, and this has been backed by scientific trials.

One study of 54 patients showed that dogs could pick up the scent of bladder cancer in a patient's urine.

Another showed that dogs could not only detect cancer, but they could tell the difference between people with breast and lung cancer, just from smelling their breath.

The latest findings were reported at a meeting of the American Physical Society in San Antonio, Texas.

Can you imagine the possibilities of your Havanese if you can tap into that sense of smell - learn how to use what they smell? I think about it all the time and would love to use it in some fashion.

I wonder if they could tell today was going to be a hot one.