Possible Causes of Dog Tongue Discoloration

Possible causes of dog tongue discoloration vary across dog breeds and the age of the dogs. The dog's tongue is an important organ that can be an indicator of illness. It is used to aid in digestion and swallowing and also for regulating the body temperature.

Dogs keep cool by panting and by drooling from their tongues. The discoloration of a tongue can occur from foreign bodies such as chewable toys having artificial colors. However, if the tongue gets discolored by licking or chewing other objects, a checkup is essential. This helps in confirming if the transferable dye is not poisonous for your dog. This result will also depend on the age of your dog. Oral problems can be a contributing factor to a discolored tongue. It is advisable to get your dog's oral problems checked to determine any changes in the dog's teeth or gums.

Black Tongue

One of the few breeds of dogs that does not have a pink tongue is the Chow Chow. Chow Chows have black tongues. If you have a dog breed that should have a pink tongue, take him to a vet if it is black. "Black tongue" occurs due to ulceration or inflammation in the mouth along with blood-stained drooling saliva. The dog's breath also turns foul. Black tongue can also be due to a deficiency of niacin. This tongue discoloration illness can become fatal if not treated in time.


Uremia causes a discolored and ulcerated tongue. It usually occurs at terminal stages of kidney failure, wherein the kidney is unable to filter urea and other toxins from the body. In some cases, obstructions in the urinary tract might be preventing proper excretion. This can be treated by surgical operations. Apart from tongue discoloration, symptoms include foul breath with a tinge of ammonia. This is accompanied with a loss of appetite, vomiting or diarrhea. Convulsions and coma can also occur in severe cases. Fluid replacement is the usual method of treatment. The dog's diet should consist of high-quality food supplemented with water-soluble vitamins.


Another possible cause of dog tongue discoloration is cyanosis. Mixed breed dogs might have colored spots on their tongues. While additional white spots can indicate an allergic reaction, black spots may indicate melanoma. Melanoma is a form of cancer. A bluish tongue color can indicate cyanosis. Cyanosis occurs due to lowered oxygen in the blood. It can occur as a result of various conditions such as respiratory disease, heart disease, or exposure to toxins. A blue tongue discoloration can be monitored for heart disease with the following symptoms:

  • decreased stamina
  • exercise intolerance
  • difficulty in breathing
  • excessive coughing in the night
  • discoloration of other mucous membranes such as gums

A dog usually collapses during a heart attack. He may show excessive activity immediately before the collapse. Dogs can suffer from congestive heart failure, where either the left or right side of the heart gets affected. The weakened heart is unable to pump blood efficiently. This results in a lack of oxygen in the brain and muscles, finally leading to a collapse.