Blue (Cyanotic) Gums in Cats

Key Takeaways

Blue gums are the most noticeable symptom of cyanosis. Cyanosis is the blue or purple discoloration of mucous membranes or skin caused by poor oxygenation. 

• Any initial onset of cyanosis is an emergency

• Cyanosis in cats can result from a number of underlying conditions including: congenital heart disease, respiratory disease, exposure to toxins, hypothermia, blood clots, shock, or the application of a tourniquet

• Diagnostic testing includes physical examination, arterial blood gas measurement, other blood tests, and diagnostic imaging

• Cats with dangerously low oxygen levels are often stabilized with supplemental oxygen immediately upon presentation

• Treatment and prognosis depend on the underlying cause

A Closer Look: What is Cyanosis in Cats?

Cyanosis is an emergency, immediate medical attention may be crucial in saving the animal's life.

There are two types of cyanosis: 

Central cyanosis affects all the animal's tissues. It is caused by the decrease of oxygenated blood throughout the body as a result of heart or lung problems. 

Peripheral cyanosis is localized, and the discoloration affects only one specific part of the body. 

Differentiating between central and peripheral cyanosis is not always easy, and either condition indicates a need for emergency care.

Possible Causes

Cyanosis is caused by poor oxygenation. A number of underlying conditions and risk factors can lead to cyanosis, including:

• Hypothermia • Blood clots • Application of a tourniquet • Congenital heart diseases • Aspiration pneumonia

• Ventricular or atrial septal defect • Heart failure • Anaphylaxis • Pulmonary fibrosis

• Airway obstruction (choking) • Respiratory muscle failure (e.g. tick paralysis, spinal cord injury)

• Narcotic overdose  • Lung blood clot (pulmonary thromboembolism) • Lung infections• Lung cancer 

• Chylothorax • Pneumothorax • Pyothorax • Hemothorax

Several chemicals can restrict a cat’s hemoglobin from correctly delivering oxygen to the body.  These chemicals include:

• Nitrates (found in soil and water, or food additives) • Acetaminophen • Methylene blue• Some topical anesthetics

Risk Factors

Short-nosed (brachycephalic) breeds (e.g. Persian, Himalayan, Shorthair, Burmese) are more likely to develop cyanosis. Blue gums are often accompanied by panting. Unlike dogs, panting in cats is a symptom of severe distress and medical attention is warranted.

Testing and Diagnosis

A cat presenting with severe cyanosis may require supplemental oxygen before diagnostic testing can begin. 

Once stabilized, a cat presenting with cyanosis usually undergoes the following diagnostics:

• Arterial blood gas test (ABG): the ABG test involves obtaining a sample of arterial blood while the animal is receiving oxygen supplementation 

• Diagnostic imaging • Pulse oximetry  • Blood tests

Treatment of cyanosis is dependent on the underlying cause.

Similar symptoms

Blue gums are unique and self evident, but cyanosis may be confused with pale or gray gums in the early moments of development of the symptom.

Associated Symptoms

Symptoms that are commonly seen in association with cyanosis:

• Lethargy • Weight loss • Difficulty breathing • Panting • Rapid breathing • Poor coat condition