sandcracks

/ˈsændˌkræks/
noun
  1. Vertical cracks or fissures in a horse's hoof, usually starting at the bottom and extending upward, often caused by dryness or injury.
    • The stable owner checked each horse's hooves regularly for sandcracks.
    • If sandcracks are left untreated, they can cause lameness in horses.
    • The farrier treated the horse's sandcracks by applying a special hoof conditioner.