Horses with full, well-developed hocks tend to have less incidence of bone spavin than those with narrow, thin hocks. A large percentage of horses affected with blind spavin recover completely. Jack spavin is usually a bony growth of variable size. The cause of bony growth cannot be fully explained. When the hock is flexed or bent, pain is produced and as a result the hindlimb is not raised very high.
Treatment consists of alleviating as much pain as possible.
By cutting the tendon veterinarians can remove one source of pain. However, the outlook for full recovery from jack spavin is usually not favorable even with surgery. The horse will probably be useable, but rest and time are needed for repair to occur. If the condition is caused by conformation or too straight hocks, it cannot be treated successfully. Veterinarians have many factors to consider in order to determine the cause and to advise the best treatment.