Hoof crack is considered as one of the serious problem that can affect horses. Based on my country, there is a significant decrease in number of horses that are affected by hoof cracks. The reason for this is the racing circumstances and training of horses is much better now. The hooves can last for long time because the ground is soft and better.

Generally, people who have a pet horse or riding horse are the one facing hoof cracks frequently. One of the reasons for this is lack of general information on what kind of horses can be exercised. Another reason are deficient in knowledge on how to properly take care of the horses and what kind of circumstances the horse can spend the time on stable, pasture and paddock.
It is impossible for a horse to manage this kind of problem, and therefore the owner or caretaker must actively participate in order to prevent hoof cracks in the horse.
One of the reason why a horse are affected by hoof cracks is when they are trotting and galloping in the hard ground. The hoof can acquire a strong concussion when it hits the ground, a same way a person falls and hit his head. Whenever hoof hits the ground, there is a risk of hoof crack.

The hoof does not have shock absorber. So, flexible and soft ground is a way better for the horse hoof.
Another reason that can affect hoof is Laminitis. A very dry horn of hoof can cause cracks because it loss some flexibility.

There are many reasons why hoof cracks occur. Improper shoeing, bad heels, and razor-sharp stones can contribute in hoof crack.

Different weather condition can also cause hoof crack. Too dry and too wet floor can be a risk for this problem.
Heel cracks are hard to manage compare to other cracks. They will need to remove infection first before treating it.