Cyanosis in Cats

Two different categories of cyanosis exist, central and peripheral. Central cyanosis involves the entire blood supply having reduced amounts of oxygen and can be life-threatening. All tissue throughout the body is affected. Central cyanosis is often the result of severe disease, defect, or poisoning. Peripheral cyanosis occurs when only one location of the body is experiencing poorly oxygenated blood supply. Usually, it is a limb or tail that is affected. Local blood flow reduction is often connected with blood stream obstructions or tourniquets on the limb. Cyanosis can happen at any age, but if it is found in a young cat, a genetic defect is often the underlying issue.

When there is diminished oxygen in the blood, it changes color to a blueish tone.The off-colored blood, in turn, gives tissue color a blue, purple, or brownish tinge. Tissue color changes are termed as cyanosis, and are an indication of a health problem within the body. Health issues that result in lack of oxygen to the blood, a condition referred to as “hypoxia”,  generally have to do with diseases of the heart and lungs or ingestion of harmful toxins.

While the most obvious symptom of cyanosis is the discoloration of visible skin, the common underlying causes of cyanosis carry many more complicated signs. Symptoms may develop rapidly, and need immediate veterinary attention. Signs to watch for are as follows:

• Blue/purple/brown color of the lips, tongue and gums
• Blue/purple foot pads
• Lethargy 
• Anorexia
• Weight loss
• Dehydration
• Difficult or open-mouth breathing
• Tachypnea (rapid breathing)
• Tiring easily
• Poor coat

There are numerous causes of cyanosis development in cats. Cyanosis itself is not a health issue, but a symptom of health issues within the body. Causative diseases often are related to the heart and lungs. Poisoning is another common underlying issue. Possible causes include:

• Airway obstruction (possibly from tumor growth)
• Thromboembolism (a blood clot that develops from heart problems)
• A tourniquet created on purpose or by accident 
• Shock
• Respiratory paralysis
• Hypoventilation
• Atrial septal defect leading to right to left shunting (blood bypasses lungs)
• Tetralogy of fallot (four coexisting heart defects)
• Hypothermia
• Pneumothorax (gas in the chest cavity that collapses the lungs)
• Pleural effusion (fluid in the chest)
• Severe pneumonia
• Muscle disorder or failure
• Acetaminophen (Tylenol) ingestion
• Carbon monoxide poisoning
• Hydrogen cyanide exposure

Once you bring your cat to a veterinary clinic or animal hospital, it may need to be stabilized before any diagnostic testing can be performed. Certain underlying issues severely interfere with breathing and can be fatal if not treated. Once the cat is in a sustainable condition, the veterinarian will perform a complete physical examination and will listen to the heart and lungs of the cat. You will need to provide the vet with your cat’s full medical history. 

The first test that may be run is an arterial blood gas measurement. A blood sample taken from an artery is monitored while receiving oxygen supplementation. The blood will clear if lung disease is the underlying issue, and will not if an obstruction or poisoning has occurred. Pulse oximetry is another noninvasive test that provides a continuous reading of blood through the armpit or groin while oxygen is supplied. 

An ultrasound of the heart may be needed to see any defects are present. Electrocardiography may also be required if heart complications have been identified. Thoracocentesis can be used to remove a sample of fluid or gas in the chest cavity for testing. A transtracheal wash can help identify any bacterial infections in the lungs. Blood work including a complete blood count and a biochemical panel can help reveal the overall health of the cat. 

Appropriate treatment will depend on the underlying health issue in the cat. Central cyanosis is a medical emergency and requires immediate attention, often involving the placement of the cat into an oxygen chamber.

Congenital Heart Disease 

If defects of the heart are found, surgical correction may be necessary. Heart surgery carries serious risks and requires the use of general anesthetic. If blood clots have been found, often a heart defect is the cause. 

Chemical Exposure 

Medication should be administered to counteract poisoning by Tylenol or other chemicals. N-acetylcysteine is generally used to alleviate the toxicity. Internal tissue injury should be limited and prevented where possible.

Respiratory Disorders

If fluid is present in the chest cavity, it should be removed by thoracentesis. If fluid is in the lungs, diuretics may be prescribed. If infection is present, a course of antibiotics will be needed. Oxygen supplementation may be needed to ease breathing throughout these treatments. 

Airway Obstruction 

The foreign body causing obstruction will need to be removed. Surgery is sometimes needed for complete removal. Intubation of the trachea may be needed to restore breathing before the obstruction is removed.

If your cat has undergone surgery for health problems related to cyanosis, recovery may be slow. All at-home care instructions should be followed to ensure the best possible outcome. Monitor the incision site daily to watch for swelling, bleeding or other signs of infection. Limit activity and keep the cat indoors during the healing process. A postoperative appointment will be needed to verify success of the surgery.

Congenital defects are hard to prevent, however, any cat with defects should not be bred. This can help eliminate the passing on of hereditary issues. Keep all medications and chemicals locked away in your home to ensure your cat can not access and ingest them.