Fanny might have a rare condition called vitiligo. Her owner shared on Instagram that Fanny’s black fur started changing color when she was 3 or 4 years old. The color change started on her head, gradually at first, and then quickly.
According to Fanny’s owner, “It could be vitiligo. The doctors couldn’t tell what gene it is exactly. Only her hair changed, not her skin.” Other Bernese Mountain Dogs, like @siegfriedthedog, also share this condition.
But what is vitiligo in dogs? Does it affect some breeds more than others? And how do genetics play a role in whether a dog develops vitiligo or not?
Check out Fanny’s Embark profile:
Embark testing confirmed that Fanny has 100% Bernese Mountain Dog ancestry.
What is vitiligo in dogs?
Vitiligo (pronounced “vih-tuh-lie-go”) is an autoimmune condition that can occur in both humans and animals. Vitiligo affects skin cells called melanocytes. These skin cells create a pigment called melanin. That pigment is what gives our hair and skin its color (the more melanin, the darker the color). With vitiligo, something in the body’s immune system attacks those cells, causing the skin and hair to lose color (a process called depigmentation).
In addition to humans, vitiligo can occur in dogs, cats, and horses. Vitiligo in dogs is mainly a cosmetic condition. It is not painful for dogs and does not require treatment. It’s not contagious, either, so dogs can’t spread it to each other.
While vitiligo is not painful and does not affect a dog’s health, it can have a significant impact for owners and breeders of show dogs. There are some treatments available, and some cases of remission from vitiligo. If you’re looking into treatment options, be sure to talk to a veterinarian first. Some treatments can be ineffective or cause negative side effects.
How common is vitiligo in dogs?
The first case of vitiligo in dogs was reported in 1971. We know that dogs, cats, and horses can have vitiligo, but we don’t have enough data to know how common it is in animals.
In contrast, the first known case of vitiligo in humans is ancient, occurring around 1500 BC. Vitiligo is the most common depigmenting disorder in humans, affecting ~0.5–2.0% of people worldwide.
In ancient times, people confused vitiligo with leprosy and other depigmenting disorders. That caused a social stigma around vitiligo that is unfortunately still present today. In humans, vitiligo affects both genders equally. It can develop at any age, but most cases start before age 30.
What does vitiligo in dogs look like?
For dogs, vitiligo usually shows up in young adulthood, similar to humans. It almost always starts on the dog’s face. In most dogs, this loss of pigment stays on the face or head, but sometimes it can spread to other parts of the body (like the footpads, nails/claws, paws/limbs, and neck/trunk/rump area).
Vitiligo can affect the skin cells or hair cells or both. It does not always appear symmetrically in dogs, but sometimes it does.
What causes vitiligo in dogs?
Scientists aren’t totally sure what causes vitiligo. It can run in families, which gives us a clue that it’s a hereditary condition. But how people or dogs inherit a genetic risk for vitiligo isn’t simple.
There’s no test for vitiligo in dogs because scientists haven’t yet discovered the gene that causes it. Actually, there are probably several genes that cause vitiligo, not just one (what scientists call “polygenic,” AKA “from many genes”). Scientists think that genes, the environment, stress, and other factors join together to cause the condition.
In humans, scientists have found at least 3 or 4 genes associated with predisposition to vitiligo, possibly more. A recent study found several genes that are “turned on” in vitiligo. We don’t know exactly how the disease happens, but some of those genes might be involved.
Vitiligo is associated with some autoimmune diseases in humans (like lupus, thyroid disease, and others). One theory says that when these autoimmune diseases attack the body, the skin cells get caught in the crossfire. In this theory, skin cells are “innocent bystanders” that happen to get caught up in the body’s immune response.
Does vitiligo affect specific breeds?
Breeds that are thought to be genetically predisposed to vitiligo include:
- Doberman Pinschers
- Belgian Tervurens
- German Shepherds
- Giant Schnauzers
Vitiligo has also been reported in Labrador Retrievers, Old English Sheepdogs, Bernese Mountain Dogs, Miniature Dachshunds, Newfoundlands, and some mixed-breed dogs. Purebred dogs are thought to be at higher risk for vitiligo than mixed-breed dogs.
Research at Embark
We might not yet know the answer to what causes vitiligo in dogs, but scientists at Embark are doing research to uncover the genetic causes of many preventable diseases.
Did you know that you can help us with this research? Simply by filling out Embark surveys, you’re helping scientists solve these mysteries and helping dogs like Fanny find answers about their DNA. Sign in to your Embark profile to get started!