Heritable equine regional dermal asthenia.

This research focuses on an inherited condition in horses known as Hereditary Equine Regional Dermal Asthenia (HERDA), a variant of Ehlers-Danlos syndrome. The condition exhibits symptoms like stretchy, loose, doughy skin, and can cause spontaneous skin damage and a higher frequency of corneal ulcers. Although there is no cure, palliative therapy can manage symptoms.

About HERDA

• Hereditary Equine Regional Dermal Asthenia, also known as HERDA, is an inherited condition prevalent in horses. It’s a form of Ehlers-Danlos Syndrome, a group of disorders affecting connective tissues, which support the skin, bones, blood vessels, and many other organs and tissues.
• HERDA is autosomal recessive, meaning both parents have to carry the mutated gene to pass on the disease to their offspring. An affected horse typically appears normal at birth with the disease manifesting in the first two years of its life.

Symptoms and Effects

• The most recognizable symptom of HERDA is stretchy, loose skin that feels doughy or soft to the touch. This is due to the weakened state of the connective tissues that maintain skin elasticity.
• More severe cases lead to spontaneous skin sloughing – a condition where the skin falls off without any external cause. This is followed by extensive lacerations (cuts), hematomas (swelling of clotted blood within tissues), and seromas (pockets of serous fluid in a sac-like structure) even from minor injuries.
• HERDA-affected horses are also found to have a higher than normal occurrence of corneal ulcers, which could potentially impair vision.

Diagnosis and Treatment

• Diagnosis can be established through DNA testing, which can identify not just affected horses, but also carrier ones i.e., those who carry the mutated gene but do not show symptoms themselves. It can also distinguish between normal horses and carriers, which is vital for breeding programs.
• As of now, no curative treatment exists for HERDA. The focus is on palliative therapy, centered on easing the symptoms and enhancing the quality of life for the affected horses.