Noisy Breathing in Cats: What Are Stertor and Stridor?

Unlike dogs that pant to dispel heat and communicate, cats usually make little to no sound when breathing. So if your cat is breathing loudly—and isn’t purring—there’s likely something abnormal involving their airways, or respiratory tract.

Noisy breathing in cats should be evaluated by your veterinarian, especially if it’s new.

What Is Noisy Breathing in Cats?

If you can hear without a stethoscope the sounds your cat makes, this is considered noisy breathing. The sounds are usually coming from the upper airways, which include the nose, throat, and trachea—not the lungs.

Certain cat breeds, like Persians and other brachycephalic cats, are born with very shortened nasal passages. In these flat-faced cats, noisy breathing may be normal, but it’s still something to discuss with your veterinarian. Some of these kitties may still need treatment for their noisy breathing.

Different abnormalities can cause upper airway sounds. Whether or not this is an emergency depends on where the sound is coming from (either stertor or stridor), how suddenly it started, and your cat’s other behaviors and clinical signs.

What Is Stertor in Cats?

Stertor is a lower-pitched sound made during breathing—like snoring or snorting—that usually comes from the nasal passages or the back of the mouth. It’s lower-pitched due to the more flexible tissues in these areas. These kinds of noises are common with brachycephalic cats.

Stertor is rarely dangerous or life-threatening, but it can be very uncomfortable, depending on the cause. If your cat is eating and behaving normally, discuss their symptoms with your veterinarian. However, if stertor is accompanied by lethargy or loss of appetite, take your cat to an emergency vet.

What Is Stridor in Cats?

Stridor is a higher-pitched sound caused by narrowing of the voice box (larynx) or windpipe (trachea). These more rigid tissues cause a whistling sound as your cat breathes in and out.

Because changes in these parts of the respiratory tract can lead to less oxygen reaching the lungs, stridor can be dangerous in cats. Cats that are suspected to have stridor should be evaluated in an emergency visit.

Causes of Noisy Breathing in Cats

Here are some possible causes of noisy breathing in cats:

• Respiratory infection: Upper respiratory infections are often viral but can also be bacterial or fungal. Chronic respiratory infections can lead to permanent damage of the nasal passages that no longer responds to medications.

• Dental disease: Severe dental disease can lead to inflammation of the larynx and even the nasal passages.

• Neoplasia (cancer): Multiple types of cancer, including squamous cell carcinoma, will target the respiratory tract and lead to narrowed airways and noisy breathing.

• Nasopharyngeal polyps: Benign growths in the inner ear (eustachian tubes) or back of the nasal passages can also obstruct airflow. This is usually seen in younger cats and can also result in nasal discharge and coughing.

• Obesity: Excess fat can lead to external pressure on the airways as well as a reduced ability to expand the lungs, resulting in noisy breathing (especially while sleeping).

• Abnormal anatomy: Kittens may be born with physical abnormalities like cleft palates that affect the airways. More commonly, flat-faced brachycephalic cats are born with narrowed airways and long, soft palates that can lead to noisy breathing.

Is Noisy Breathing in Cats Common?

Noisy breathing in cats is not common and usually indicates illness.

If your cat’s breathing sounds like snoring, they should be evaluated by a veterinarian. Your vet can discuss the severity of the symptoms with you and come up with a diagnostic and treatment plan if one is available.

What To Do for Noisy Breathing in Cats

A cat breathing loudly should be evaluated by a veterinarian.

If they are eating and behaving normally, keep them indoors, ideally away from excess heat or humidity, until they can be evaluated.

If the noisy breathing is accompanied by exercise intolerance, decreased appetite, or hiding, bring your cat to an emergency veterinarian.

Diagnosing the cause of noisy breathing can sometimes be done with a physical exam alone. More frequently, your vet will want to perform blood work or X-rays and may recommend testing for common bacterial and viral infections.

Severe cases or those that do not resolve with common therapies will need sedated oral exams and more advanced imaging, like a CT scan or rhinoscopy, where a small camera is used to visualize the inside of the nose and assist in taking samples of any abnormalities.

Treatment for Noisy Breathing in Cats

The treatment for noisy breathing depends entirely on the cause.

• For cats with upper respiratory infections and congestion, antibiotics, antivirals, and anti-inflammatories may be prescribed, and these cats can often be treated at home.

• Physical obstructions of the airways from masses, polyps, or foreign objects will often need surgery.

• Flat-faced cats with brachycephalic airway syndrome may need long-term environmental management, including avoiding heat and humidity and limiting exercise. Keeping these cats in ideal body condition can also help them breathe easier.

• Severely affected brachycephalic cats may also benefit from surgery such as rhinoplasty, to reshape their small noses, or a soft palate resection. These procedures help improve airflow through the back of the throat.

How To Prevent Noisy Breathing in Cats

Not all causes of noisy breathing are preventable, but there are certainly steps you can take to reduce your cat’s risk of airway disease.

• Keep up with vaccinations: Keep your kitty vaccinated against common respiratory diseases with the distemper (FVRCP) vaccine. Also, discuss other lifestyle-based vaccines, like feline leukemia, with your veterinarian. Respiratory viruses are an extremely common cause of noisy breathing in cats and many can be prevented with vaccines.

• Discuss routine deworming with your vet: Some parasites can infect the respiratory tract directly or weaken your cat’s immune system and make them more susceptible to respiratory infections.

• Maintain good dental health: Brush your kitty’s teeth with a cat toothbrush and toothpaste at home, and schedule routine anesthetic cleanings for your cat. This will help identify and even prevent inflammation that can restrict your cat’s upper airways and nasal passages.

• Provide mental and physical enrichment: Environmental enrichment and stress reduction in the home can reduce the frequency of feline herpesvirus flares, which can lead to nasal and ocular disease. Having a variety of perches at different heights—in the form of cat trees or window perches—and appropriate objects to practice normal scratching and marking behavior—like cat scratchers and scratching posts—can significantly improve your cat’s mental and physical health.

• Maintain a healthy lifestyle: Maintaining an ideal body condition with a healthy diet and exercise reduces stress on the respiratory tract. Obesity makes cats much more likely to have noisy breathing.

• Support ethical breeding: Avoid purchasing—or breeding—kittens with severely flat faces.