ACDHA – Junctional Epidermolysis Bullosa 1 (JEB1)

Description

Junctional Epidermolysis Bullosa (JEB) is an inherited disease also known as Red Foot Disease or Hairless Foal Syndrome. Variations of the disorder affect Belgian Draft horses, American Saddlebred horses, and relatives of these breeds.

This inherited disorder is caused by a mutation that inhibits the body's ability to produce certain proteins responsible for holding the skin onto the body. Affected horses are typically born alive with few symptoms. However, four to five days after birth, the foal begins to develop skin lesions at pressure points around the body. These lesions quickly grow larger, creating patches all over the foal's body.

Because the same protein responsible for skin adhesion is also involved in hoof attachment, the foal also beings to lose the hoof. Eventually, the hoof may detach entirely. Horses can develop oral ulcers and eroded enamel. Furthermore, horses born with JEB are typically born with incisor teeth. Normally, horses don’t develop teeth until approximately eight days of age.

Unfortunately, there is no cure for JEB. As the condition worsens, the foal will begin to develop severe infections. They will suffer from increasing pain and discomfort. Foals often die from these infections, or are euthanized within 3-8 days after birth.

JEB is an autosomal recessive trait, meaning that a foal needs a copy of the disease from both parents in order to develop symptoms of JEB. A carrier of JEB only has one copy of the disease and does not develop symptoms. When two carriers are bred with one another, there is a 25% chance per foal born that they will develop symptoms of JEB. There is a 50% chance per foal that they will become carriers themselves. This makes testing for JEB a valuable tool in predicting the health of foals while breeding.

Animal Genetics offers DNA testing for both the JEB1 mutation found in Belgian Draft horses and the JEB2 mutation found in American Saddlebred horses.