A hoof crack may be cause for concern or nothing to worry about. Here's a quick rundown of the type of hoof cracks you're likely to see on your horse and what the consequences of each might be.
Horizontal cracks are usually merely cosmetic and are most likely the remnants of a coronary band injury that disrupted the hoof growth. These cracks usually grow out with standard hoof maintenance.
Shallow chips and vertical fissures along the edges of a horse's hoof are also likely to be superficial. Generally caused by stress or imbalance, these cracks are commonly found in overgrown hooves. If not attended to by a farrier when minor, shallow defects can become serious.
Deep vertical cracks are serious, particularly when they are bleeding, unstable (allowing the wall to move), extend up to the coronary band and/or are accompanied by lameness. Cracks deep enough to cause any of these problems warrant the attention of your veterinarian, as well as your farrier.
The best way to prevent hoof cracks is to have your horse's hooves trimmed regularly.