Health Topics  >  Respiratory  > Coughing

What causes coughing in dogs?

An occasional cough every now and then may simply be a reaction to an irritant in the air or choking on some food. If you start to notice your dog coughing throughout the day, more frequently or exhibit other symptoms, it’s a good chance that there’s something more serious going on and you’ll want to speak to your vet.

Coughing can be a symptom of different underlying conditions, the most common being infectious bronchitis or kennel cough, but a similar sounding cough can also be a sign of allergic airway disease, collapsing trachea or congestive heart failure.

Although not a comprehensive list, the following causes have been known to cause coughing in dogs:


Canine Infectious Tracheobronchitis a.k.a “Kennel Cough” or Bordetella

Canine infectious tracheobronchitis a.k.a “Kennel Cough” or Bordetella is an upper respiratory infection which is common among young dogs. Kennel cough is not well named as it gives an easy misconception that dogs must be kennelled in order to be exposed, but it is widely spread amongst young dogs when they play or wrestle with their mouths, share water bowls, sticks, balls etc.

It is caused by a variety of microorganisms, some bacterial (Bordetella), some viral (parainfluenza virus, canine herpesvirus, canine respiratory coronavirus, etc.), often at the same time. Most cases of kennel cough do not require the use of antibiotics as the cough is typically self-limiting and resolves within a week.

Certain short-nosed breeds are more vulnerable to developing complications from the upper respiratory infection and they should be carefully monitored for signs of lethargy, inappetence, a change in the cough sound to soft, shallow or wet which can be a sign of a secondary pneumonia.

Contacting your vet about kennel cough is a good idea, some vets will suggest not coming into the clinic if your dog is otherwise acting normal in order to avoid transmission to other pets, and because most infectious coughs resolve without treatment. In this case, lots of TLC, a good plane of nutrition, isolation from other dogs while your dog is coughing (typically a week), and “steam therapy” are helpful.

Steam therapy is when you make a bathroom extra steamy using a hot shower, then allow your dog to walk around in it to loosen/soothe their chest (with the shower turned off).  If your dog develops other symptoms (decreased appetite, lethargy, change in the cough or productive discharge that has colour to it), you should bring them to your vet and they will likely want to take chest X-rays and prescribe medications.

Chronic Bronchitis

Chronic bronchitis is a chronic intermittent but often progressive (getting worse over time) cough, often with an underlying allergic cause. It can be very mild or severe, and is usually diagnosed by the process of eliminating other causes of coughing with X-rays and lab work.

Chronic bronchitis is common in older dogs, especially when there are other underlying respiratory issues present.  It cannot be cured but there are many treatment options to help manage it to allow for a good quality of life.

Exacerbating any cough with excitement or strenuous exercise is never helpful and will typically cause the cough to get worse. Allergic bronchitis is often treated like human asthma, using puffers with anti-inflammatory medications in them. Each dog responds differently to medications, however, so it’s important to discuss the treatment options available.  

Heart Disease

Coughing is the most commonly noticed sign of heart disease, and can sound just like any other cough but is often soft and continuous. It can be caused by enlargement of the heart putting pressure on the dog’s windpipe, or from congestive heart failure causing a buildup of fluid on their lungs making it difficult for oxygen to get into their bodies.

Because of this, your dog’s cough may be worse at night or when they’re resting on their side. Congestive heart failure (CHF) is typically accompanied by decreased energy and stamina, and an increased resting respiratory rate (greater than 30 breaths per minute when your dog is very relaxed).

More advanced CHF can cause episodes of collapse, blue gum colour and obvious signs that your dog is struggling to breath (using their abdomen rather than their chest to take breaths). If any of these signs are apparent, you should bring your dog to a vet immediately.


Lung tumors or lung ‘mets’ (metastatic tumors that have spread from a cancerous tumor elsewhere in the body) are seen in older dogs as a cause of chronic cough. Weight loss is often accompanied with this cough, as well as decreased energy and stamina (exercise intolerance) and sometimes other physical signs like enlarged lymph nodes or other palpable tumors.

Chest X-rays are the first step needed for diagnosis, often abdominal x-rays or ultrasound will be recommended to get a more complete picture. CT scan and referral to an veterinary oncologist will likely be discussed if cancer is suspected and you want to know all the possible treatment or supportive care options for your dog.


Pneumonia is a lung disease which is caused by inflammation of alveoli or the air sacs of the lungs. These air sacs get filled with fluid which causes coughing and difficulty in breathing in pets. It is seen as a progressive cough, typically causing lethargy, exercise intolerance, a decreased appetite and often a fever, the cough can be ‘wet’ sounding and produce phlegm.

A chest X-ray is needed to further assess for pneumonia. Your vet will likely prescribe antibiotics if pneumonia is suspected, some dogs will require hospitalization for intravenous antibiotics and supportive care while their lungs recover (oxygen supplementation).  

Fungal pneumonia

Fungal pneumonia is another infectious cause of pneumonia seen in certain geographical areas.  It is fairly rare but can be difficult to treat and is best if identified early.  It presents similar to other infectious coughs and requires X-rays and other advanced laboratory tests to be diagnosed.

Other common causes of coughing include infectious diseases such as distemper and heartworm, which can easily be prevented by keeping up with your dog’s core vaccines