What this means
A healthy dog's tongue and gums are normally pink. In some breeds the tongue is naturally blue or spotted, so it matters to know what your own dog's tongue has always looked like. A changed colour, especially together with panting, coughing or weakness, is a serious sign.
The blue colour often comes with heavier breathing, but it can show up only after exercise or excitement. Even if the colour returned to normal, that does not mean all is well, and you must tell your vet about it.
If you can safely do so, note down when the colour changed, how long it lasted and what your dog was doing at the time. A photo or a short video helps your vet a great deal.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your dog.
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Problems with the heart
When the heart cannot pump blood properly, or blood flows along the wrong routes, the tissues get less oxygen and the tongue turns blue, especially after exercise.
About the condition: Heart disease -
Narrow airways
In short-nosed breeds narrow airways stop enough air getting in, and after exercise or in the heat the tongue can turn blue.
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Narrowing of the windpipe
When the windpipe flattens, air struggles to pass, your dog coughs, and with excitement or after exercise it can turn blue.
About the condition: Tracheal collapse -
A problem with the voice box
When the muscles of the voice box do not open, breathing in is hard and noisy, and in the heat or after exercise the gums and tongue can turn blue.
About the condition: Laryngeal paralysis -
An inherited heart valve problem
Some breeds are prone to an inherited narrowing of a heart valve, which makes a dog tire fast and can turn the tongue blue after exercise.
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A naturally dark tongue
In some breeds the tongue is blue or spotted from birth. That is normal, but you need to know what your dog's tongue looked like before.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- What your dog's usual tongue and gum colour is
- When the colour changed: after exercise, at rest, in the heat
- Whether there is also coughing, panting or noisy breathing
- Whether your dog tires sooner on walks
- Whether there was weakness, collapse or fainting
- How long the colour stayed changed
When to book a routine visit
Even if the colour went back to normal, tell your vet and book as soon as you can, because it can be a sign of a heart or breathing problem. If the tongue or gums are blue now, go immediately.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Heart disease Heart This is an umbrella term for various conditions in which the heart muscle, the valves or the heart rhythm stop working as well, making it harder for the heart to pump blood around the body. Some are present from birth, others develop with age, and they can go a long time without any noticeable signs. During a check-up the vet listens to the heart and decides whether further tests are needed.
- Brachycephalic airway syndrome Breathing In short-muzzled dogs the nostrils, nasal passages, soft palate and throat are packed into very little space, so air has a harder time getting through. These dogs work harder to breathe than others, especially in heat, when excited or after exertion, and that can turn into real danger. How much it affects a particular dog varies a great deal, so their breathing is worth talking over with a vet.
- Tracheal collapse Breathing Tracheal collapse is a condition in which the cartilage rings of the windpipe weaken and the windpipe flattens, making it harder for air to reach the lungs. It tends to get slowly worse over time, and excitement, heat, pressure on the neck or excess weight can make breathing even harder.
- Laryngeal paralysis Breathing Laryngeal paralysis is a condition in which the cartilages of the larynx no longer open properly when the dog breathes in, because the nerves and muscles that move them weaken. Less air reaches the lungs, and the dog struggles to cool down, since dogs shed heat by panting. If a dog is struggling to breathe, its gums turn blue or it collapses, it needs a vet immediately.
- Pulmonic stenosis Heart Pulmonic stenosis is a heart defect present from birth, in which the outflow of the right ventricle, at or near the pulmonary valve, is narrowed, restricting the path blood takes to the lungs. To push blood through the narrowing the right side of the heart has to work harder, and its muscle thickens over time. The defect ranges from barely noticeable to severe, so how much it has affected the heart is for a vet to assess.