Thrush is most common during the damp and wet seasons. It also has a smelly odor which can be identified by a bad onion smell. It is known by black goo that is found on the edges of the frog. It takes root in the soft tissues of the hoof which is located near the frog. When treated quickly it can be easy to get rid of, but if not taken care of it can be hard to treat and will take a few weeks to get under control.