Ehlers-Danlos Syndrome in Dogs

Ehlers-Danlos Syndrome, also called Cutaneous Asthenia, is a rare genetic disorder of the skin. It has been found in dogs, humans, cats, cows, and sheep. Hippocrates knew about it in 400BC, but it was eventually named after the scientists that characterised the disorder: Edvard Ehlers and Henri-Alexandre Danlos.

What is Ehlers-Danlos?

Ehlers-Danlos Syndrome occurs when the connective tissues of the body don’t form properly. Collagen is one of the main tissues that bind our body together, and if an animal is collagen-deficient due to a genetic problem then the tissues don’t work effectively. In Ehlers-Danlos affected animals, the collagen has an abnormal structure which causes weakened collagen and in turn weak tissues. In Ehlers-Danlos, the most common body part affected in dogs is the skin, which becomes loose and prone to breaking and tearing. Ehlers-Danlos affects all collagen-containing structures to different degrees, so it’s also possible that the eyes, heart and blood vessels are affected. There have been a few cases of the joint form of the disease in dogs, but it is much more common in people.

Who gets Ehlers-Danlos?

Ehlers-Danlos syndrome is thankfully rare. It affects all breeds of dogs but especially the Springer Spaniel. It affects both males and females equally. Since dogs are born with the disease, it is most commonly diagnosed in young animals (less than three years of age) but in mild cases can remain undiagnosed. Very severely affected animals will often die in the first few days.

Ehlers-Danlos is a genetic disorder. It is thought to be “autosomal dominant”, which means that they only need to inherit one copy of the gene to show signs. Dogs with Ehlers-Danlos should not be bred- even if the other dog is normal there is a 50% chance of any puppies having the disease. The problem is that there’s no genetic test to see if a dog is affected, and some mildly affected dogs could go on to breed normally, so spreading the condition.

What are the symptoms of Ehlers-Danlos?

The symptoms of Ehlers-Danlos depend somewhat on which part of the body is mainly affected. The most common sign is that of skin hyperextensibility; how stretchy the skin is. Whilst normal patients have an extensibility of 8-15%, Ehlers-Danlos dogs range from 17-25%. This skin is extremely prone to damage and as such these dogs often have a history of cuts and scrapes, many of which will have scarred excessively or struggled to heal. Most of the cuts will have been from very minor things- knocks against furniture or groomers teasing our knots are enough to cause a large, gaping cut. Dogs with Ehlers-Danlos have been to the vets multiple times to have wounds stitched, and may have had difficulty with even surgical wounds such as neutering scars.

Dogs with the joint form of Ehlers-Danlos will be intermittently lame on all four limbs. They may have knee joints that pop and click, or they may stand in an abnormal position. When examined by a vet, it may be noted that their limbs are a bit more flexible than usual, and that the joints bend abnormally.

If the eyes are affected, premature clouding is one of the most common signs, although a blue tinge to the eyes, eyes that point in different directions, and severe pain and sudden-onset blindness are all other signs of Ehlers-Danlos in the eyes.

The type that affects the heart is likely to cause early death and as such is rarely seen in pets older than a year.

Other symptoms include excessive bruising, rupturing of the diaphragm, hernias and difficult administration of medications given intravenously due to the weak blood vessels. Difficulty giving birth is another sign associated with Ehlers-Danlos, as the uterus is weaker than it should be.

How can we confirm the diagnosis?

In dogs with extremely fragile skin, a presumptive diagnosis is often made based on the skin hyperextensibility. Whilst under an anaesthetic the vet pulls the skin of the back and measures the maximum size of the skin flap created. They then compare this to the size of the dog.

For a definite diagnosis or for more complex cases, a skin biopsy can be taken. This can often be done under a light sedation. A small section of skin is taken out and sent to the laboratory for testing. They will slice it thinly and examine under the microscope. Very thin skin and haphazardly arranged collagen fibres are classic findings.

Can Ehlers-Danlos be treated?

Unfortunately, there is no treatment for Ehlers-Danlos. Some animals that are severely affected may have to be euthanised due to the welfare impact of having such fragile skin. The majority of animals can go on to live normal lives, albeit with far more injuries and surgery than would be considered normal. They can live as long as an unaffected dog.

Can I do anything else to help?

Prevention of injury is the best way to ensure your dog’s welfare. Take a look around the home and decide whether there’s anything sharp that could cause injury- furniture corners, protruding screws and broken tiles are all risks that should be removed or barriers placed. Your dog’s nails should be kept short and blunt, so that any itching is less likely to damage the skin. You should also take steps to prevent unnecessary itching, for instance with preventative flea treatment. Try to walk away from vegetation and sharp thorns- you may need to adjust your garden, too. Make sure that any wounds are treated immediately and let the vet know that your dog suffers with Ehlers-Danlos so that they can take care and use the correct stitch type to give them the best chance of healing. Ehlers-Danlos dogs take longer to heal than other animals, so ensure that any surgery, planned or otherwise, is given plenty of time to heal before removing stitches.