Hereditary Equine Regional Dermal Asthenia (HERDA)

Hereditary Equine Regional Dermal Asthenia

Turnaround: 3-5 business daysTurnaround: 7-10 business days

Price: $35.00Price: £28.00

Breeds: American Indian, Appaloosa, Appaloosa Cross, Appaloosa/Friesian, Appaloosa/Quarter Horse, Appaloosa/Thoroughbred, Appendix, AraAppaloosa, Arabian/Paint, Arabian/Quarter Horse, Australian Stock Horse, Azteca, Baroque Pinto, Canadian, Cleveland Bay, Clydesdale/Paint Cross, Colonial Spanish Horse, Crossbred, Friesian Cross, Grade Horse, Grade Pony, Miniature Appaloosa, Mixed Breed, Mixed Breed (Horse), Morgan Horse, Origine Constatée, Paint Cross, Paint Horse, Paint Horse/Thoroughbred, Paint/Warmblood, Ponies of America, Pura Raza Espanola, Quarter Cross, Quarter Horse, Quarter Pony, Quarter/Paint Horse, Quarter/Stock Horse, Quarter/Thoroughbred, Quarter/Warmblood, Spanish Barb, Spanish Mustang, Stock Horse, Stonewall Sporthorse, Sugarbush Harlequin Draft, Thoroughbred, Unspecified, Welsh Mountain/Quarter Horse


Hereditary Equine Regional Dermal Asthenia (HERDA) is also known as Hyperelastosis Cutis (HC). HERDA is a genetic skin disease predominantly found in the American Quarter Horse. Researchers at Mississippi State University and Cornell University believe that the origin of this genetic disorder may be the Poco Bueno's sire line.

The primary symptom of this disorder is a lack of adhesion within the layers of skin. This is due to a genetic defect in the collagen (a fiber with in the body) that holds the skin in place. This defect causes the outer layer of skin to split or separate from the deeper layers. Sometimes these layers tear off completely. Areas under the saddle seem to be most prone to these lesions. There are often permanent scars which prevent the horse from being ridden.

The disorder is recessive, which means that a horse must have two copies of the defective gene to suffer from the disease. A horse with only one copy of the mutation is known as a carrier, and does not present any symptoms. When two carriers are bred with one another, there is a 25% chance per foal born that they will develop symptoms of HERDA. There is a 50% chance per foal born that they will inherit a copy of the mutation and also become carriers of HERDA. This makes testing an important tool while breeding.

Although there is no cure for the disorder, Animal Genetics has developed a simple DNA test in order to detect a single nucleotide polymorphism (SNP) mutation with a high degree of association to this disorder. This makes the test easily available to our customers.

Possible Results

Genotype Description
Hrd/Hrd Affected: Horse is has two copies of the HERDA gene mutation and will exhibit signs of the disorder. Horse will pass on the gene to all offspring.
N/Hrd Carrier: Horse has one copy of the HERDA gene mutation. Horse has a chance of passing this gene on to any offspring.
N/N Clear: Horse is negative for the HERDA gene mutation.