Junctional Epidermolysis Bullosa (Discovered in the Australian Cattle Dog Mix)

Junctional Epidermolysis Bullosa (JEB) is a severe skin disorder that causes skin fragility and blistering, as well as potentially significant irritations in the oral cavity. The associated genetic variant has been identified in Australian Cattle Dog mixes.

Found in

1 in 6,300 dogs

in our testing

Key Signs

Fragile skin, Skin blistering, Oral lesions, Nail loss, Stunted growth, Failure to thrive, Death

Age of Onset

0 to 2 yrs

Juvenile onset


Autosomal Recessive

For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.

Likelihood of the Condition

High likelihood

At risk dogs are highly likely to show signs of this disease in their lifetime.

What to Do

Here’s how to care for a dog with JEB

Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.

For Veterinarians

Here’s what a vet needs to know about JEB

Epidermolysis Bullosa is a group of inherited disorders characterized by skin fragility and multifocal skin blistering and ulcerations. The type known as Junctional Epidermolysis Bullosa is indicative of the involvement of the epithelial basement membrane. In affected dogs, ulcerations may appear within days to weeks after birth and often in areas of high friction, such as the oral cavity, ears, abdomen and paw pads. Thick crusts covering deep erosions and ulcers of the skin, particularly of the inner pinnae (ear flap), paws, and pressure points on the limbs, may occur. Affected puppies may also slough their nails. Ulcers can also be found at mucocutaneous junctions, like the lips, genitalia and anus, as well as in the oral cavity. Owners may report frequent choking while the puppy is eating or drinking. Affected puppies may be significantly smaller than littermates, likely as a result of discomfort associated with eating. In addition, affected puppies can demonstrate tachypnea (increased respiratory rate) with prominent inspiratory stridor (noisy inspiration). The disorder carries a poor to guarded prognosis with severely affected puppies not surviving past a few months of age.

Treatment is pain management, supportive care, and symptomatic depending on the severity of the dog's clinical signs. This may also include owners altering the dog's environment to reduce potential for trauma to the skin. Unfortunately, JEB carries a poor prognosis and humane euthanasia may be elected depending on quality of life.

For Breeders

Planning to breed a dog with this genetic variant?

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disorder is autosomal recessive, meaning two copies of the variant are needed for a dog to be at an elevated risk for being diagnosed with the condition. A carrier dog with one copy of the Junctional Epidermolysis Bullosa (Discovered in Australian Cattle Dog Mix) variant can be safely bred with a clear dog with no copies of the Junctional Epidermolysis Bullosa (Discovered in Australian Cattle Dog Mix) variant. About half of the puppies will have one copy (carriers) and half will have no copies of the variant. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disorder signs similar to the ones associated with this Junctional Epidermolysis Bullosa variant could develop due to a different genetic or clinical cause.

Technical Details

Gene LAMA3
Variant T>A
Chromosome 7
Coordinate 64,427,161

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Herrmann, I., Linder, K.E., Meurs, K.M., Friedenberg, S.G., Cullen, J., Olby, N., Bizikova, P. (2021). Canine junctional epidermolysis bullosa due to a novel mutation in LAMA3 with severe upper respiratory involvement. Vet Dermatol, 32(4) ,379-e108. View the article