You might not think much about your dog’s tongue, but it plays an important role in their overall health. It helps them eat and drink, assists with temperature regulation and grooming, and even contributes to communication. While most dogs have pink tongues, some have blue or blue-black tongues because of genetics and pigmentation. In most cases, this coloring is harmless. However, a sudden change in tongue color can sometimes signal a medical emergency.
What Causes Dogs to Have Blue Tongues?
If your dog has a blue tongue, it most likely comes down to genetics.
“There are some dogs that have a bluish tongue, really more dark purple, and this can be due to breed and melanin, which gives the tongue a different color,” says Dr. Sarah Carotenuto, DVM and Assistant Professor at the University of Arizona College of Veterinary Medicine.
Melanin is a natural pigment that colors skin, hair, and eyes. It’s common for dogs to have darker pigmentation on certain areas (called “points”), including their nose, lips, paw pads, and around their eyes. When a dog’s tongue appears blue, black, or dark purple, it’s typically due to a high concentration of melanocytes, the cells that produce melanin.
This process is similar to how birthmarks or freckles develop in people. In some dogs, the increased pigmentation affects the tongue, gums, or other parts of the mouth.
Researchers still don’t fully understand why certain breeds develop entirely blue tongues. However, studies suggest that the trait is linked to a small number of genes. Genetic research in Chow Chows has pointed to two specific genes, ASIP and PDPK1, both linked to pigmentation in several other animal species.
Not all dark tongues are solid blue. Some dogs develop blue-black spots or patches instead. These pigmented markings may be present at birth or appear later in life. Your dog might be more likely to have a dark or blotchy tongue if their parents have one. Fortunately, this type of pigmentation is generally harmless and doesn’t affect a dog’s health.
Which Dog Breeds Have Blue Tongues?
Only a small number of breeds are known for having entirely blue or blue-black tongues:
- Chow Chow
- Chinese Shar-Pei (except dogs with certain dilute pigment variations)
- Eurasier
- Thai Ridgeback
In these breeds, tongue color usually isn’t fixed at birth. Puppies typically start with pink tongues, and the blue or blue-black coloring develops gradually over the first several months — in Chow Chows, for example, the color change usually begins between 8 and 10 weeks of age and can continue for up to six months before reaching its final appearance.
As these dogs age, some may develop pink spots where the pigmentation fades. That’s considered normal, and it’s also seen in dogs with dilute coat colors, such as blue or cinnamon.
Why Do Some Dogs Have Blue-Black Spots on Their Tongues?
If your dog has blue-black blotches on their tongue, it doesn’t necessarily mean they have Chow Chow ancestry.
According to Dr. Carotenuto, these pigmented spots can occur in any dog but are more commonly seen in breeds with darker pigmentation. Australian Shepherds, Australian Cattle Dogs, and many other non-white breeds may develop blue-black markings on the tongue.
High levels of pigmentation can also create dark spots on other parts of the body, including the roof of the mouth and the stomach area.
Breeds commonly reported to have blue-black tongue spots include:
- Akitas
- English Cocker Spaniels
- German Shepherd Dogs
- Golden Retrievers
- Labrador Retrievers
- Mastiffs
- Newfoundlands
- Pomeranians
- Siberian Huskies
You’ll also often see pigmented tongue markings in spitz breeds with curled tails. Although many spitz breeds share ancient ancestry with Chow Chows, there is no evidence that tongue pigmentation alone confirms a direct connection.
When Is a Blue Tongue a Medical Concern?
Any new or changing spots on your dog’s tongue deserve your prompt attention.
Oral cancers, particularly melanomas, are common in dogs. If you notice a raised lump, inflammation, bleeding, discoloration, or a newly developed growth on the tongue, schedule a visit with your veterinarian.
It’s especially important to seek veterinary evaluation as soon as possible if these changes occur alongside signs such as:
- Weight loss
- Bad breath
- Excessive drooling
- Decreased appetite
Catching tongue melanomas early and starting treatment quickly gives dogs the best chance at a good outcome.
In some situations, a blue or purple tongue can indicate a medical emergency rather than normal pigmentation.
“As veterinarians, we get concerned when a dog whose tongue has never been blue or purple suddenly turns this color, especially if it is accompanied by difficulty breathing,” Dr. Carotenuto explains. “Blue or purple in these instances often means cyanosis, which means that the blood is unable to properly oxygenate.”
“Of course, if your animal just snarfed down a blue lollipop or popsicle and has a teal tongue and is otherwise normal, it’s probably okay to monitor at home,” Dr. Carotenuto clarifies.
Cyanosis most commonly occurs in dogs with conditions that affect how oxygen moves through the body, including heart defects, lung disease, neuromuscular disorders, or breathing problems such as tracheal collapse.
If your dog suddenly develops a blue or purple tongue, contact your veterinarian immediately.
For most dogs, a blue or blue-black tongue is simply part of who they are — no different from a distinctive coat pattern or eye color. But because tongue color can also be a window into your dog’s health, it’s worth knowing what’s normal for your dog and getting anything new or different checked out.