What Is Stertorous Breathing In Cats?

What is stertorous breathing?

Stertorous breathing, commonly known as stertor, refers to loud snoring or gasping sounds during breathing caused by partial obstruction of the upper airway (Merriam-Webster, 2022). The term “stertorous” implies a harsh, low-pitched noise originating in the nose or throat (Nationwide Children’s Hospital, 2022). Stertor occurs when air passes through a partially obstructed airway, causing vibrations of the pharyngeal and laryngeal tissues (Dictionary.com, 2022).

What causes stertorous breathing in cats?

Stertorous breathing in cats is typically caused by some kind of obstruction or fluid buildup in the upper airways. The most common causes include:

Upper airway obstructions: Obstructions like foreign bodies, masses, abscesses or tissue swelling in the nasal passages, throat or larynx can lead to noisy breathing. Polyps, viral infections and cancer growths are some examples. The obstruction blocks normal airflow and causes turbulence and vibration of tissue, resulting in stertorous sounds.

Fluid in the throat or lungs: Fluid buildup from conditions like pneumonia, pleural effusion, pulmonary edema or heart failure can cause fluid to accumulate in or around the lungs. This interrupts normal airflow and causes abnormal breath sounds. Cats with heart disease are prone to pulmonary edema, which is a buildup of fluid in the lungs.

Tumors or masses: Cancerous growths in the nasal cavity, pharynx, larynx or lungs are potential causes of airway obstruction and subsequent stertorous breathing in cats. fast-growing nasal tumors are particularly common in cats. These masses block airflow and create noisy respiratory sounds.

Symptoms of stertorous breathing

The main symptom of stertorous breathing is a loud snoring or snorting sound when the cat inhales. This is caused by airway obstruction or constriction in the throat or nose. The breathing may sound raspy, noisy, congested or have a “rattling” quality to it.

Other symptoms may include:

  • Audible wheezing or whistling when breathing in or out
  • Noisy breathing even when awake and alert
  • Labored or difficult breathing with prolonged inhales and exhales
  • Flared nostrils as the cat struggles to get air
  • Breathing with an open mouth or head extended to maximize airflow
  • Lethargy, fatigue or shortness of breath
  • Decreased appetite or activity due to breathing difficulty

If stertorous breathing is chronic or occurs while the cat is awake and active, it signifies a potentially serious lower airway or neurological problem requiring veterinary assessment.

Diagnosing the cause

If a cat is exhibiting signs of stertorous breathing, the first step is to take the cat to the veterinarian for a full physical exam and diagnostic tests. The vet will listen closely to the cat’s breathing using a stethoscope, feeling for any raspy, snoring-like sounds. They will also check the mouth, nose and throat for any obstructions, inflammation, masses or foreign objects that could be blocking the airway.

Imaging tests like x-rays or an ultrasound of the nose, throat and chest area may be recommended to get a closer look at the structures and identify an underlying problem. X-rays can reveal masses, abscesses or fluid accumulation, while an ultrasound allows for a detailed view of the soft tissues and airway. These imaging tests help pinpoint the cause of stertorous breathing, whether it is a tumor, polyp, infection, injury or anatomical abnormality.

Treatment Options

The treatment for stertorous breathing in cats focuses on addressing the underlying cause:

Surgical removal of obstructions – If a foreign object, mass, abscess or other obstruction in the nasal passages or throat is causing the stertorous breathing, surgery may be done to remove it. This can help open the airway and resolve breathing issues.

Medications – Antibiotics, steroids, bronchodilators, or other medications may be prescribed depending on the cause. Antibiotics treat infections, steroids reduce inflammation, and bronchodilators open constricted airways.

Treating medical conditions – Any underlying illnesses contributing to stertorous breathing will need to be managed, such as asthma, heart failure, respiratory infections, etc. This supportive medical care is key.

The specific treatment approach will depend on the vet’s diagnosis for what is causing the cat’s noisy breathing. Prompt veterinary attention is important to identify and properly treat the cause.

Providing supportive care

Supportive care is an important part of treatment for cats with stertorous breathing. This can help manage symptoms and improve comfort while addressing the underlying condition.

Some key aspects of supportive care include:

  • Oxygen therapy – Providing supplemental oxygen can help cats who are struggling with low oxygen levels. This may involve use of an oxygen cage, mask, or nasal cannula under veterinary guidance. Oxygen therapy helps reduce respiratory distress and support breathing function.
  • Rest and stress reduction – Allowing ample rest and reducing stress is vital to support breathing. This may involve confining the cat to a small, quiet space and limiting activity and stimulation. Reducing stress and exertion can help reduce respiratory effort.
  • Keeping airways clear – Using humidification, suctioning, and medications can help keep airways open and clear secretions. Saline nebulization may be used to moisten and loosen mucus. Cough suppressants, mucolytics, and bronchodilators may also be used under veterinary direction.

While addressing the underlying condition, supportive care measures help ensure the cat’s immediate breathing needs are met. This maximizes comfort until the stertorous breathing can be resolved.

Home care tips

If your cat has stertorous breathing, there are some things you can do at home to help manage their condition:

Monitor breathing – Keep a close eye on your cat’s breathing and watch for any worsening of symptoms. Look for increased effort or changes in the sound of their breathing. Contact your vet right away if you notice a decline.

Avoid stress – Try to minimize stressful situations for your cat, as anxiety can exacerbate breathing issues. Keep their environment calm and quiet.

Contact vet if worsening – Even with supportive care at home, stertorous breathing can worsen over time. Alert your vet immediately if your cat has increased difficulty breathing or if the stertor becomes louder.

While home care can provide comfort, underlying causes of stertorous breathing need to be addressed. Work closely with your veterinarian to determine the right treatment plan for your cat’s condition.


The prognosis for a cat with stertorous breathing depends on the underlying cause (1). Some causes like respiratory infections or obstructions can often be successfully treated or managed with medication, while other causes like cancer may have a more guarded prognosis. According to WagWalking, if treatment is possible, the prognosis is often better (2). However, even with treatment, some degree of breathing issues may persist long-term.

Research shows that many of the potential causes of stertorous breathing can be successfully treated if caught early (1, 3). Bacterial or viral respiratory infections generally respond well to antibiotics or antivirals. Foreign objects lodged in the nasal cavity or throat can usually be removed through endoscopic procedures. Obstructive masses like polyps or tumors may require surgery but can oftentimes be fully removed. Other issues like allergies, asthma, or dental disease can be controlled through medications and lifestyle management.

Overall, the prognosis for a cat with noisy breathing depends greatly on the specific cause and how quickly treatment can be started. But many underlying causes can be successfully managed to significantly improve quality of life and breathing function if addressed promptly under veterinary care.


(1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7158197/

(2) https://wagwalking.com/cat/condition/noisy-breathing?page=2

(3) https://www.petmd.com/cat/conditions/respiratory/c_ct_noisy_breathing


There are some steps cat owners can take to help prevent stertorous breathing in their cats:

Monitor for signs of obstruction: Pay close attention to any signs your cat may have something stuck in their airway or nasal passages, like gagging, wheezing, open-mouth breathing, coughing, or pawing at their face. Catching an obstruction early can prevent more severe breathing issues.

Treat conditions early: Managing underlying conditions like asthma, allergies, respiratory infections, and heart disease can reduce flare ups that lead to noisy breathing episodes. Keep up with vet checkups and medication as prescribed.

Avoid irritants: Limit exposure to things like smoke, dust, and strong smells that can irritate your cat’s respiratory system.

Maintain a healthy weight: Carrying excess weight puts more strain on the respiratory system. Follow your vet’s feeding recommendations to keep your cat at an optimal weight.

Consider supplements: Some supplements like L-lysine may help strengthen the respiratory system against infections that can cause congestion and noisy breathing [1].

When to seek emergency care

Stertorous breathing can become a life-threatening emergency if your cat has trouble breathing, becomes lethargic, or collapses. According to PetMD, you should seek immediate veterinary care if your cat is showing signs of respiratory distress such as:

  • Severe difficulty breathing – gasping for air, breathing with an open mouth, etc.
  • Turning blue or extremely pale in the gums and tongue
  • Collapsing or sudden weakness and inability to stand
  • Unconsciousness

Lethargy and collapse are worrying signs that indicate your cat is not getting enough oxygen due to an obstruction or inflammation in their airway. Per the NCBI source, a collapsed airway can quickly become fatal if not treated immediately. If your cat is struggling to breathe, contact an emergency vet right away for proper diagnosis and potential oxygen therapy or other interventions to reopen the airway.

According to Vetster, even mild stertorous breathing warrants a vet visit to determine the underlying cause. But if your cat shows signs of severe respiratory distress, do not wait – seek emergency veterinary care immediately to save your cat’s life.

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