Cyanosis in dogs: What it looks like and how it’s treated

Cyanosis is when the gums, tongue, or other mucous membranes turn a bluish to gray color, showing that the blood isn't getting enough oxygen. In dogs, cyanosis is most easily recognized on the gums and tongue and is generally considered an emergency sign. If you notice your dog’s gums, tongue, or lips have suddenly or unexpectedly turned bluish or gray, it’s important to treat this as an emergency and seek veterinary care right away rather than trying to manage your dog’s condition at home. Cyanosis is almost always considered a medical emergency.

Even though cyanosis always represents insufficient oxygen levels in the blood, there are many potential causes for cyanosis in dogs, including various heart, respiratory, and systemic conditions. A veterinarian can identify the underlying cause and recommend treatments that not only address the immediate crisis but also reduce the risk of future episodes, giving your pet the best chance at recovery and long-term health. To help you learn more about cyanosis so you can quickly identify an emergency, we’ll cover:

• Heart problems that can cause cyanosis in dogs
• Symptoms that indicate an emergency
• How the cause of cyanosis in dogs is diagnosed and treated

At a veterinary clinic, the immediate goal is usually to stabilize a cyanotic dog with supplemental oxygen and to minimize stress. Additional steps depend on the cause of the cyanosis and can include medications and treatments to remove fluid buildup and improve heart function.

Sudden development of blue or gray mucous membranes typically indicates an emergency requiring prompt in-person evaluation. If you’re unsure whether your dog’s gums, tongue, lips, or skin look normal and there are no other obvious signs of illness like lethargy, collapse, or breathing difficulty, an online consultation can be a helpful first step. A virtual veterinarian can review what you’re seeing without the need for potentially stressful transportation, provide guidance on whether it appears urgent, and advise you if in-person care is needed.

Cyanosis is a clinical finding of abnormally bluish to grayish appearing mucous membranes, which include the gums, lips, or tongue, caused by low oxygen levels in the blood. Oxygen gives blood its red color, but as oxygen levels drop, the red shifts to blue. Veins will have a bluish hue when they return low-oxygen blood back to the heart and lungs. Because tissues like the gums and tongue have a good supply of oxygenated blood, they appear pink, unless the color is masked by a dog’s naturally occurring blue or black pigment. Cyanosis is often accompanied by other symptoms.

“Cyanosis is a symptom of a much larger health problem with the heart, lungs, blood, or circulation rather than an illness itself,” explains Dr. Jo Myers, a veterinarian on the Vetster platform. “It is almost always considered an emergency.” If you notice cyanosis in your dog for the first time, it indicates a potential emergency. In some cases, dogs with certain chronic conditions may develop cyanotic gums, lips, or tongues. In these cases, follow your veterinarian’s instructions on what to do.

Possible causes of cyanosis in dogs

In order to successfully treat cyanosis, it’s important to identify the underlying cause. While cyanosis in dogs can result from a disease of the respiratory system, such as severe pneumonia or an airway obstruction, or systemic issues, such as severe anemia, this article focuses on cardiac causes.

Heart problems that can cause cyanosis include:

• Congestive heart failure
• Severe arrhythmias
• Structural heart disease, such as valvular disease or dilated or hypertrophic cardiomyopathy
• Congenital heart disease
• Advanced heartworm disease
• Pericardial disease (pericardial effusion/tamponade)

Congestive heart failure (CHF), heart arrhythmias, and dilated cardiomyopathy (DCM) are common heart conditions seen in dogs. Heartworm disease is also common, but cyanosis is only rarely associated with it. Pericardial disease occurs when excess blood or fluid accumulates in the sac that surrounds the heart (pericardium). This puts pressure on the heart so it can’t pump properly. While not as common as conditions like valve disease or cardiomyopathy, pericardial effusion is an important cause of heart failure signs in some dogs, particularly large breeds.

The following clinical signs are medical emergencies that require immediate in-person veterinary care:

• Sudden, abnormally bluish or gray colored gums, lips, or tongue
• Collapse, loss of consciousness, or weakness
• Labored breathing
• Restlessness, anxiety, or inability to settle

The presence of these signs is often associated with a medical emergency, and in-person evaluation is the most reliable way to determine what’s happening and how best to help your dog. While it’s natural to want to look for answers online, using that time to reach a veterinarian instead is far more valuable when your pet may be facing an emergency. If you’re unsure if your dog’s tongue, gums, or lips are normal and your dog is otherwise acting fine, an online vet can help by examining your dog and offering advice on what to do next.

Cyanosis is usually easy to identify during a physical examination and can be measured with a pulse oximeter, a device that measures blood oxygenation by shining light through through thin, hairless tissues that normally have good blood flow, such as the tongue or lip. Pulse oximetry is a quick and noninvasive way to estimate the blood’s oxygen saturation, but arterial blood gas analysis is the definitive assessment when available. Both methods measure the dog’s oxygen levels but do not explain why the dog is cyanotic. Diagnostic tests are necessary to determine what’s causing the gum, lip, or tongue discoloration. Testing may involve:

• Blood work
• Electrocardiogram (ECG)
• Cardiac ultrasound (echocardiogram)
• Chest X-rays

The first step in treating a cyanotic dog is often stabilizing the dog by restoring adequate oxygen levels in the blood. If the dog is in respiratory distress, stabilization methods, such as supplemental oxygen therapy, may be given before diagnostic tests are done. A cyanotic dog may be placed in an oxygen cage to decrease stress until they’re stable enough to be held for tests. Treatment to target the underlying cause varies depending on the diagnosis and may involve:

• Diuretic medication
• Medications to improve heart function
• Drainage of excess fluid in the chest
• Surgical intervention to correct heart defects
• Heartworm treatment

Prognosis varies dramatically depending on the underlying condition, how that condition responds to treatment, and whether the dog can be stabilized.

Information to tell your veterinarian

Important information that may help your vet in the diagnostic process includes:

• Whether the discoloration is persistent or changes with rest or activity
• Anything that occurred before the symptoms started
• When the symptoms started and how long they’ve been happening

Taking a photo or video of your dog’s symptoms while at home may also be helpful, but only if it doesn’t delay care; getting to an in-person vet as quickly as possible is the top priority.

It can be frightening to see your dog’s gums turn blue or gray. Immediately seeking veterinary care any time you notice signs of cyanosis in your dog can make a big difference to the outcome. Some causes of cyanosis can be treated successfully if addressed promptly, while others, such as advanced heart disease, cannot be cured but may be managed for a period of time.

If your dog’s skin, tongue, or gums turn unexpectedly blue, gray, or purple, this indicates a need for immediate in-person veterinary attention. Keeping your dog calm and minimizing stress during transport is often helpful. If your dog has a chronic heart disease or other condition where cyanosis is to be expected from time to time, developing a plan for what to do at home can help both you and your dog get through a difficult situation.

Pet owners with supplemental oxygen at home for human use may wonder if it’s beneficial to use it on their cyanotic dog. Using oxygen prescribed for a human is unlikely to benefit your dog in the case of an emergency. Attempting to administer oxygen to an uncooperative or stressed dog can make cyanosis worse as they struggle. Similarly, over-the-counter recreational oxygen products are highly unlikely to provide meaningful benefit in an emergency. Trying to use oxygen products that aren’t prescribed for your dog can waste precious time when the priority should be getting your pet to a clinic where effective treatment is available.

If you’re unsure if your dog’s skin, gums, lips, or tongue are a healthy color, an online veterinary professional can examine them virtually, discuss any symptoms, and offer professional advice on what to do next.

What does it mean if my dog has blue skin, lips, or gums?

Abnormal and unexpected blue skin, lips, gums, or tongue indicates cyanosis. Cyanosis occurs when oxygen is not being adequately delivered to tissues around the body due to an issue with a dog’s lungs, heart, red blood cells, blood vessels, or circulation. The symptom is usually considered an emergency and indicates a need for immediate, in-person veterinary care. Home care alone is unlikely to address the underlying problem, and delaying veterinary attention can make it more challenging to stabilize and treat your dog. Seeking in-person care as quickly as possible gives your dog the best chance for a positive outcome.

How do vets treat cyanosis in dogs?

Veterinarians often start by trying to stabilize cyanotic dogs by giving them supplemental oxygen to increase blood oxygen levels. Once a dog is stable enough to be handled, diagnostic tests, such as blood work and diagnostic imaging, are usually necessary to determine the underlying cause of the cyanosis. Treatment methods vary depending on the cause but may include heart medication, injury stabilization, toxicosis treatment, surgery, and blood transfusion.

What should I do if my dog’s gums are turning blue?

If your dog’s mucous membranes or skin unexpectedly turn abnormally blue or gray, this indicates a need for emergency veterinary care. This color change is called cyanosis and is caused by your dog not getting enough oxygen. Cyanosis is almost always a medical emergency.

Disclaimer: This article, its content, and its related references do not constitute veterinary advice and should not be considered a substitute for veterinary care. If your pet is showing any symptoms that could indicate a medical emergency, please seek immediate emergency care.