For dogs, the sense of smell is just as important as the sense of sight for us. It is their most important sense. And according to the scientist, it's 10,000 to 100,000 times better than ours. Its hard to imagine, but we can make analogy to vision. Imagine that you can see 10 000 times better than you do now. That would be incredible wouldnt it? That is why the smell is so important for dogs.
People only have 6 million receptors in our nose, while dogs do have 300 millions of them. Another dog advantage is, that they have two different air passagese, one for breathins and another one for smelling! This means that they do not lost the smell, when they are breathing out – just like we do.
They also have better brain – well at least for smelling. If we would talk in brain ratio – the part of dogs brain that is analyzing the smell is 40 times bigger than ours. As you can see, dogs are just made for sniffing.
Dogs also have ability to sniff independently from each nostril. That is why they can track where the scent is coming from much more accurate than we do.