HC/HERDA UPDATE; OWNERS OF CARRIER STALLIONS NOTIFIED

HC/HERDA

Approximately 100 Quarter Horse stallion owners have received, or will receive, a telephone message from Ann Rashmir, DVM, MS, Dipl. ACVS, associate professor of surgery and head of the Hyperelastosis Cutis (HC) Research Program at Mississippi State University (MSU), that contains unwelcome news. The message is that the stallion is a carrier of the recessive gene that causes HC, also known as hereditary equine regional dermal asthenia (HERDA).

When a horse has HC, there is lack of adhesion within the dermis, the deep layer of the skin, due to a collagen defect. Collagen serves a form of glue that holds the skin layers together. In horses with HERDA, the "glue" is inferior and the skin layers separate.

In dramatic cases, the skin can split along the back and even roll down the sides, with the horse literally being skinned alive. Generally speaking, she says, the average lifespan for an HC horse is two to four years.

Here is a horse showing classic signs of HC/HERDA on the body. Click here for stories on HC/HERDA.

SEE BOTTOM OF PAGE FOR IMAGE CREDITS.

HC/HERDA hock

The hock of a horse with HC/HERDA.

HC/HERDA skin lesion

Skin lesions on an HC-afflicted research horse at MSU. The lesions rarely heal without disfiguring scars.

 

HC/HERDA pinch

Rashmir shows how easily the layers of the skin separate on a horse with HC.

HC/HERDA skin folds

HC/HERDA back

The back and side of a horse with HC.

HC/HERDA side

HC/HERDA Paints

Cindy Lyles of Haslet, Texas, bred her mare and did an embryo transfer. When flushed, the mare produced two viable embryos and each was implanted in a surrogate mare. Two foals were born (one is shown above). Both of them demonstrated outward signs of HC early in their lives. Further analyses, including biopsies, proved they were afflicted. Lyles has donated the two colts to the HC research herd at Mississippi State University.

HC/HERDA Paints

HC/HERDA Paints

 

TOP SEVEN IMAGES: COURTESY ANN RASHMIR, DVM, MS, DIPL. ACVS. BOTTOM THREE IMAGES (PAINTS): COURTESY CINDY LYLES