Reduction in hoof quality and damage to the inner sensitive structures typically happen over time - most often without any outward signs. It is not wise to wait until the symptoms and signs of injury are apparent and the horse is in obvious discomfort.
Healthy change in hooves is brought on in miles - not just months. It does require time to reverse the damage - and it can be done in the majority of cases. The transition can be challenging but the rewards are priceless. As long as the horse is comfortable (with or without boots), the horse will self exercise and should be ridden.
Keep in mind that proper nutrition (give the horse what it needs to repair and grow tissue from within), regular natural trimming (promote the physical and mechanical means to develop, stimulate and maintain the horse's hooves for use on all terrains) and plenty of exercise (a.k.a miles - to develop tough calloused frogs and soles) WILL RESULT IN STRONGER, HEALTHIER, SOUND HOOVES.
Some hooves may not result in textbook perfect form. The goal is healthy hooves with strong material and structure which are able to perform with comfort based upon the needs of the individual.
A side note about THRUSH: Keep thrush out of your horse's hooves! Attack it with a vengeance. The infection can progress from discomfort to severe pain at the heels which will cause the horse to land on its toes. This leads to more problems - The negative affect this has on the mechanics of the horse's movement then affects the development and soundness of the structures of the hoof. It is imperative that the horse maintain a heel first landing.
Please endeavor to learn all that you can and make informed decisions based on science, research, evidence and knowledge - for your horse's sake.
Chigger's last founder was in 2008 - it was severe; she would not stand even to graze.
Natural trims got her up and running, pulling a cart on the gravel driveway.
Kona wore shoes until 2008 - they were removed and he has been natural ever since.
He has been ridden on rocky trails at Cedars of Lebanon and on the dirt trails of Percy Warner with ease.