To track a tracking dog needs a track. This sounds simple but is very important if you try to track big game.
To explain, what is meant by that, let me give you an example. Imagine you have bottle of perfume and you throw it on the ground. What happens is, that you have an enormous scent everywhere in you apartment. It will be hard for you to locate, where exactly the bottle fell to the ground.
After some time, maybe hours the scent begins to disappear and you will be able to smell the general location, where the bottle fell. After some additional time you can locate the exact spot. If you do that with many bottles in a row in the end you will have many little spots of scent or a track.
That is what happens if an animal you want to track, runs through the woods. First you have a big cloud of scent and the dog has no orientation where to go. But after some hours, the cloud shrinks to a tunnel the dog can follow. A track develops and leads the dog to the wounded game. Do not start to early. Wait at least 4 hours (more is better) before you start to track.