If you have a puppy born with a lovely pink tongue, and you suddenly notice black spots or markings appear, should you worry?
Myths about black tongues on dogs abound. Some say these dogs are more aggressive and others say they are smarter. Naturally, we expect dark blue or purple-black mouths in Chow Chows or Shar Peis. So when black spots appear on the tongue of a purebred Labrador Retriever or Golden Retriever, you may wonder if they’re purebred.
Or can black spots or markings on the tongue mean there is a medical problem we should be paying attention to?
What does it mean when dogs have black spots on their tongues?
Many dogs born with perfect pink tongues will develop black spots or markings on their tongues over time. It simply means that they have areas on their skin with more pigment, or melanin, that darkens the skin. Very rarely, a black spot on the tongue can mean cancer or a nutritional deficiency.
It does not mean your dog has any Chow or Shar Pei ancestry, but they may share a common ancestor with these breeds, which we will discuss below. It also doesn’t mean your dog has an oral hygiene problem, although that doesn’t mean you should skimp on that doggy mouthwash unless you want to have to look for doggy dentures, or filling for cavities.
Dogs with black coloring on their tongue, the time of their eyes or mouth, ears, paw pads, or nails are said to have “dark points”. Many will on develop these dark points over time. Even Chows and Shar Peis are famous for a completely black, dark blue, or purple tongue, and are born with pink ones that gradually darken.
On the other hand, if you notice that your dog’s gums are pale, see our article on white or pale gums as it is likely an emergency.
Is it normal for dogs to have a black mouth?
It’s entirely normal for dogs to have black spots on their tongue and elsewhere. It’s just like freckles or a birthmark. Dogs have all kinds of different pigmentation colors and patterns on their body. Mostly, this is because of “domestication syndrome.”
In studies on foxes, foxes who were selected for years to be friendly to humans developed all kinds of new coat patterns (and got floppy ears and wagging tails like dogs). In fact, it’s well-known that any domesticated animal has a much wider range of colors.
While we don’t fully understand all the mechanisms behind this, it probably has to do with hormones. Because domesticated animals like dogs are bred to be friendly to people, their hormones change to help them become more friendly and docile.
Since melanin is a hormone, pigment and color is one of the first things to change. This is how animals like dogs get random black or brown spots on their body and patches of white. Still, black tongues and black spots happen more in some breeds than others.
Which Dog Breeds Have Black Tongues?
While the Chow Chow and Chinese Shar Pei are the dog breeds most famous for having black tongues, really nearly any breed may have them. Because it’s usually just a bit of extra pigment, like freckles or birthmarks, any breed can have a black spot or two.
This means if your dog has black, dark blue, or purple spotted tongues, it does not mean they are descended from Chow Chows or Shar Peis.
But some breeds, like German Shepherds, are more prone to black markings in the mouth. This means your Shepherd Pei is very likely to have a blue-black tongue. But here is a list of other dogs besides Chows and Shar Peis that often have black tongues:
- Airedale Terrier
- Alaskan Malamute
- Australian Cattle Dog
- Australian Shepherd
- Belgian Shepherd
- Belgian Malinois
- Bichon Frise
- Black Russian Terrier
- Bouvier des Flandres
- Cairn Terrier
- Cocker Spaniel
- Doberman Pinscher
- English Setter
- Retrievers (Flat-coated, Golden, & Labradors)
- German Shepherd
- Kerry Blue Terrier
- English Mastiff
- Thai Ridgeback
- Rhodesian Ridgeback
- Shiba Inu
- Siberian Husky
- Soft-coated Wheaten Terrier
Why do some dogs have black or blue tongues?
There are some interesting possibilities as to why some dogs have black tongues.
3. Dogs with black mouths probably had a common ancestor
We don’t really know why breeds like Chow Chows and Shar Peis have blue-black or purple tongues, but we do know that they have a common ancestor. This means the original dogs that people eventually bred into these two breeds likely had a black tongue.
We can also notice several interesting clues as to why some dogs have black tongues. By looking that the different breeds that are more likely to have dark mouths, we notice that:
- It is common in Spitz breeds that have thick coats and tails that curl over their back. This includes the Akita, Malamute, and Husky.
- It is common among Mastiff breeds, like the Tibetan and English Mastiff.
- It is common in breeds from England, such as Setters, Retrievers, and Spaniels.
- It is common in dogs from Asia.
So what does this tell us? Well, we know the Chow Chow has qualities similar to the Mastiff and the Spitz Breeds. Many Spitz breeds moved to other areas of Asia, giving many Asian dogs that curved tail we see in Shiba Inus.
Meanwhile, Mastiff-type dogs were found across Europe and Asia, and likely landed in England with the Roman war dogs, the Molossers. The original Mollossers were probably dogs very similar to the Tibetan Mastiff, with thick coats. These early mastiffs probably became distant ancestors of many English breeds.
So what does this tell us? It is very likely that an ancient breed of dog, probably older than 3000 years, gave rise to the Spitz and Mastiff breeds and had a black tongue. As the nomadic ancient people spread across the globe, they took this dog with them, and it gradually evolved into the many purebred dogs with black tongue spots we know today.
2. The original dog with a black tongue probably came from somewhere cold
As many Spitz breeds, and ancient mastiffs like the Tibetan Mastiff may have black markings on their tongues, it’s likely their original ancestor came from somewhere cold. Very cold.
For one thing, spitz breeds like Huskies and Greenland Dogs, and the Shar Pei all have DNA from extinct prehistoric Siberian wolves that lived in the last ice age. For another, some of the breeds with black tongues are among the oldest dogs in the world, including the Chow, Greenland Dog, Tibetan Mastiff, and Malamute.
Interestingly, another Arctic predator, the Polar bear has a blue-black tongue just like the Chow and Shar Pei. The dark coloring is a way to preserve heat.
Is it possible that domesticated prehistoric wolves that are now extinct also had black or blue tongues to preserve body heat in the last ice age? If they did, they may have passed it on to many dog breeds across the globe.
When to worry about a black spot on your dog’s tongue
Even though black spots on a dog’s tongue usually just mean a bit of extra pigment, occasionally it can be something more serious. Here are two scenarios to look out for.
Black spots on dog tongue and cancer
Occasionally, a black spot on a dog’s tongue might be oral cancer. Be on the lookout for a spot that grows rapidly, has irregular edges and color, becomes an open sore, or is raised like a wart. Sometimes these spots are dark in color, but they can also be smooth lumps or look like bits of cauliflower.
Other symptoms include:
- Bad breath
- Excessive drooling
- Pain in the mouth area
- Difficulty eating
- Swollen face
- Weight loss.
Black tongue in dogs due to deficiency
Very rarely, a dog’s tongue may turn black from a niacin or vitamin B3 deficiency. This causes black tongue disease and it’s the canine version of human pellagra.
Dogs get niacin from the amino acid, tryptophan. This is found mostly in red meat, fish, and poultry (especially in Turkey). You can also get it in nuts, legumes, and seeds. Since dogs don’t eat many nuts and seeds, and legumes are linked to taurine deficiencies, dogs who don’t get sufficient meat and protein in their diets are most at risk of Black Tongue Disease.
Are dogs with black tongues aggressive?
Dogs with black mouths are not more aggressive than other dogs. There is absolutely no evidence or reason to believe this is true. However, some people may believe this because many breeds with black tongues or black spots on their tongues are known for being more aggressive.
This includes Akitas, Shar Peis, Thai Ridgebacks, and protection breeds like the Belgian Malinois and German Shepherd. However, breeds known for their friendliness and lack of aggression like the Golden or Labrador Retriever, or the Newfoundland, also often have black spots on their tongues. So the color of a dog’s mouth or tongue says nothing about their temperament.
Are dogs with black tongues smarter?
Dogs with black tongues and spots on their tongue are definitely not smarter than any other dog. Chows and Shar Peis, the breeds who are most well-known for their dark tongues, are notoriously difficult to train and not particularly smart.
Dog psychologist Stanley Coren explains that Chows rank 76 out of 79 in trainability and believes that there is furniture that is easier to train.
On the other hand, the German Shepherd, Golden Retriever, and Belgian Malinois are among the cleverest breeds in the world and they often have black markings on their tongue. So black tongues are not an indication of a dog’s intelligence.
Black spots on a dog’s tongue are the normal type of pigmentation that can show up in any dog but appears in some breeds more than others. Interestingly, the breeds most prone to markings on their tongue may share a single, ancient ancestor.
Nevertheless, when cleaning your dog’s mouth, always make sure to keep an eye on any black spots in case they show signs of becoming tumors.
Tamsin De La HarpeAuthor
Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions.
Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.