HERDA is a genetic defect that causes the skin to become thin and brittle. As a result of the condition, injuries or pressure on the skin that causes tears will not heal properly. The result is a very fragile-skinned horse with diminished usefulness. The bloodline carrying this defect has not been released. Indications are that this defect traces back to a single horse and not all horses from that bloodline are affected. Therefore, the information will not likely be released until researchers know exactly which horses are at risk. Additionally, horses with similar bloodlines but not carrying the defect will not be adversely affected.
