4 Medical Reasons Your Cat Coughs When Purring [According to a Vet]
Dear Dr. T.,
We adopted our 4 year old kitty a few months ago from a shelter. I’m trying to figure out why my cat coughs when purring and rarely at any other time. She is indoors only and seems healthy except for the coughing and gagging while purring. What would cause this?
A cough that’s triggered by purring points to a problem in the cat’s larynx. The purring action vibrates the irritated throat tissue, leading to a coughing fit. Laryngeal problems include upper respiratory infection, laryngitis, foreign objects, tumors and laryngeal paralysis.
Is It Normal for a Cat to Cough When Purring?
Although it’s not normal for a healthy cat to cough when purring, it’s not uncommon when there is a problem with the upper respiratory tract.
A cat’s upper respiratory tracts starts with the nostrils (or nares) which are openings on the outside of the nose that allow air to flow in and out of the body. Cats have a system of sinuses in their skull that are lined by mucus membrane tissue. The sinuses warm, moisten and clean inspired air before it is drawn into the lungs.
Air flows from the sinuses into the “voice box,” or larynx, before entering the lower respiratory tract by way of the windpipe (trachea). The tissue that lines the upper respiratory tract does a good job of trapping dust, pollen and micro-organisms to prevent them from getting into the lungs. But that means the sinuses and laryngeal tissue are prone to irritation, inflammation and infection.
Now, let’s take a look at how a cat makes the purring sound. The muscles around the larynx relax and contract in a quick rhythm, making the vocal cords vibrate. This happens in conjunction with a rhythmic contraction of the cat’s diaphragm. (1)
So, when a cat with laryngeal irritation starts purring, the inflamed tissue is jostled and tickled by the rhythmic motion of the purr. Nerves send signals to the brain that something might be in the larynx that shouldn’t be there. The brain then makes the cat cough in an effort to clear the irritated larynx.
Now, let’s go over the most common causes of laryngeal irritation in cats…
Post-nasal Drip from Upper Respiratory Infection
Upper respiratory infection (URI) is very common in cats. In fact, most cats have had one by the time they reach adulthood. URIs are most often caused by viruses but we also see bacterial and fungal infections. Cats with viral URI may also have a secondary bacterial infection of their sinuses.
URI in cats can occur acutely, but some cats never completely clear the infection or suffer from tissue damage after the infection. These cats develop chronic symptoms of URI which may include nasal discharge, coughing, loud breathing and sneezing.
Whether acute or chronic, URI can lead to post-nasal drip. That’s when mucus from the sinuses flows backward toward the throat. The vibration caused by purring can dislodge this mucus and cause a tickling sensation in the larynx that leads to coughing and/or gagging.
Treatment is aimed at reducing mucus production and decreasing inflammation in the upper respiratory tract. Vets often turn to antibiotics and anti-inflammatory medications for this.
The prognosis for cats with chronic upper respiratory symptoms is good to fair. They can live a normal life but often have recurring symptoms.
A cat’s larynx is part of the upper respiratory tract and is attached to the back of the sinuses and the front of the windpipe/trachea. The larynx contains the cat’s vocal cords and the epiglottis which is like a tiny lid to keep anything other than air from getting into the trachea.
Since the larynx is at the junction of the upper and lower respiratory tracts, it is exposed to a lot of debris and microorganisms. That’s why it’s not unusual for cats to experience inflammation of this area, a.k.a. laryngitis. Common causes include viruses, bacteria, fungi, allergens or airborne irritants like smoke.
Symptoms of laryngeal inflammation in cats may include change in meow or purr quality, coughing, coughing set off by purring, drooling, trouble swallowing, hard swallowing and poor appetite and weight loss.
Effective treatment of laryngeal inflammation in cats depends on identifying the underlying cause. Your veterinarian may recommend blood tests, xrays and possibly an exam of the larynx while your cat is under anesthesia.
The prognosis is good to fair in many cases of viral or allergic causes. Your cat may need to take medication to control chronic inflammation.
Growth or Foreign Object in Throat
Occasionally, upper respiratory or laryngeal symptoms in cats are caused by an object in the area. The object may be in the form of an inflammatory polyp, a cyst, a benign or cancerous tumor or even a foreign object such as a piece of grass or food.
The symptoms of a growth or object in a cat’s upper respiratory tract often include changes in voice, noisy breathing, trouble swallowing, coughing, gagging, not purring or coughing when purring, nasal discharge, bleeding from the nose or mouth, very bad breath, and even respiratory distress.
Before treatment can be tried, your vet will need to get a good look to see if there is a foreign object or growth present. Special imaging procedures like CT scan, MRI, and endoscopy are often required. Sometimes foreign objects can be removed during endoscopy. Biopsy and culture sample can also be collected during the procedure.
The prognosis for recovery from upper respiratory foreign bodies is often good. Benign tumors that can be fully removed have a better prognosis than cancerous tumors.
When vets talk about laryngeal paralysis, we’re usually talking about dogs. But it occasionally happens to cats, too. Laryngeal paralysis is a disease in which one or both sides of the larynx become paralyzed.
Paralysis of the larynx means the larynx can’t open wide enough to let air in and the vocal cords can’t make normal sounds. Other symptoms include voice changes, noisy breathing, and coughing. Some cats don’t have any noticeable symptoms at all.
Some causes of laryngeal paralysis in cats include trauma, polymyositis and cancer. But in most cases, the cause is never identified.
Treatment of symptomatic laryngeal paralysis involves surgery to permanently hold the larynx open so air can flow freely. The prognosis for cats with laryngeal paralysis is generally poor, but there are reports of cats who had surgery surviving for at least 11 months. (3)
- A coughing cat needs to be examined by a veterinarian. Home treatment is not an effective or reliable solution in most cases.
- Coughing that happens mainly when a cat purrs indicates involvement of the larynx.
- Infection, inflammation, masses and foreign objects are the most common reasons cats cough during purring.
- Since feline asthma affects the lower respiratory tract and not the larynx, it’s less likely to cause a cough triggered by purring.
- Radiographs, MRI/CT and endoscopic imaging are often required to make a diagnosis. Biopsies and cultures are other common parts of the workup for cats with these symptoms.
- Depending on the cause, the prognosis may range from good to guarded.
- Remmers, J. E., & Gautier, H. (1972). Neural and mechanical mechanisms of feline purring. Respiration physiology, 16(3), 351-361.
- Schachter, S., & Norris, C. R. (2000). Laryngeal paralysis in cats: 16 cases (1990–1999). Journal of the American Veterinary Medical Association, 216(7), 1100-1103.
- Thunberg, B., & Lantz, G. C. (2010). Evaluation of unilateral arytenoid lateralization for the treatment of laryngeal paralysis in 14 cats. Journal of the American Animal Hospital Association, 46(6), 418-424.
- White, R. N. (1994). Unilateral arytenoid lateralisation for the treatment of laryngeal paralysis in four cats. Journal of Small Animal Practice, 35(9), 455-458.