Every dog can learn to track!
The dog's nose is exceptionally powerful. The olfactory field of a medium-sized dog is around 15 times larger than that of humans; it has more than 220 million receptors (humans have around 5 million). This means that the dog is able to perceive smells even in the lowest concentration, far beyond human imagination.
Tracking training in a sporting sense means that, in contrast to mantrailing, the dog does not look for the human's individual scent, but rather follows the smell of the ground damage.