Pneumonia in Dogs

Causes, Treatment, and Prevention

Dog coughing with white background

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Pneumonia can affect your dog's lungs, making it difficult to breathe and if left untreated it can even become a life-threatening condition to your pet. Understanding how to reduce your dog's risk of getting pneumonia and being able to recognize the symptoms of this disease can help you prepare to care for your pet.

What Is Pneumonia?

Pneumonia is a disease that affects the lungs. Inflammation inside the microscopic parts of the lungs called air sacs causes swelling, pus, and fluid that makes it difficult for a dog to breathe. Lungs are not normally filled with fluid or pus so when they are, there is less room for air to fill these balloon-like structures in the chest.

Symptoms of Pneumonia in Dogs

The signs of pneumonia in dogs are often the same as in people. If the dog is not medically evaluated and treated, the symptoms will worsen and they will not resolve on their own.


  • Discolored or bloody mucus from the nose or after a cough
  • Fever
  • Difficulty breathing
  • Discolored mucous membranes
  • Loss of appetite
  • Lethargy/fatigue

Discolored or Bloody Mucus

This mucoid discharge is typically green, yellow, or even bloody (when there is an infection). Infections are quite common with pneumonia. Colored mucus can be seen coming from the nose after a productive cough.


A rectal body temperature over the normal 101 to 102.5 degrees Fahrenheit is indicative of a fever, which is also usually seen in a dog with pneumonia, due to the secondary infection inside the lungs.

Difficulty Breathing

Anytime the lower respiratory tract is compromised there may be difficulty breathing. This is most easily recognized with short and shallow breaths that can turn into hyperventilation and coughing deep in the chest which may produce mucus.

Discolored Mucous Membranes

Your dog's mucous membranes may be discolored and take on a shade of blue, gray, or purple if it is suffering from pneumonia. Check your pet's mucous membranes, which can include its gums, genitals, nasal passages, and around the inside of the eyes to see if there are any colorations. Discoloration occurs when not enough oxygen is coursing through a dog's system.

Loss of Appetite

In addition to the other symptoms, a dog with pneumonia simply doesn't feel well so it often doesn't eat much, if at all. Your dog also won't want to eat because it is unable to smell its food.


Since the lungs aren't able to work efficiently in a dog with pneumonia, oxygen isn't being moved throughout the body very well. This will result in your pet acting listless and feeling exhausted.

Causes of Pneumonia

Pneumonia can be caused by irritation, injury, or more commonly an infection of the lungs. Some examples of these causes include:

  • Inhaled irritants: Aerosol sprays, smoke, air pollutants, and other inhaled irritants may cause inflammation in the lungs and result in pneumonia. Pets who live in homes where their owners smoke are more likely to develop lung issues just like their human counterparts.
  • Aspiration: Aspiration is when food or other liquid or solid material is accidentally inhaled into the lungs. This can be seen in a dog that has been vomiting. It is also a potential complication associated with anesthesia.
  • Diseases: Many diseases can affect the dog's immune system or compromise its respiratory tract including megaesophagus, cleft palate, laryngeal paralysis, and others. These diseases can make a dog more likely to develop a bacterial infection in the lungs which causes pneumonia.
  • Viruses: Secondary bacterial infections and inflammation due to viral infections such as parainfluenza, canine adenovirus type-2, and canine flu may occur in a dog and cause pneumonia. These viral infections are often easily spread from dog to dog.
  • Bacteria: The most common cause of pneumonia, bacteria such as Escherichia coli, Pseudomonas aeruginosa, Bordetella bronchiseptica, Streptococcus zooepidemicus, Pasteurella multocida, Klebsiella pneumoniae, and different Mycoplasma species often lead to infections that result in pneumonia. These bacteria may even spread from dog to dog.
  • Trauma: If an injury to the chest occurs, a dog may develop inflammation in the lungs. Pneumonia can result from being hit by a car, falling off a balcony, or any other chest injury.

Diagnosing Pneumonia in Dogs

A veterinarian will perform a full physical examination on a dog after an owner notes symptoms that are characteristic of pneumonia. The vet will also examine the dog's nasal discharge, coughing, temperature, and lungs. If pneumonia is suspected, the doctor will perform further diagnostic tests, including the following:

  • X-rays of the lungs will check for fluid and inflammation.
  • A bronchial lavage (a wash of the cavity) will be performed to check if bacteria are present in the lungs.
  • A sample of the nasal discharge or lung fluid from the lavage may be sent out for a microbial culture or cytology to see what type of bacteria is causing pneumonia.
  • Bloodwork is often checked to see if there's an elevation in the white blood cell count which can indicate a systematic infection.


Pneumonia is serious and can be life-threatening to a dog, so it is typically treated in a veterinary hospital. The staff will monitor your dog's breathing and administer medications and procedures to help manage the illness. Here are the types of treatments you can expect your dog to receive for pneumonia:

  • Antibiotics
  • Anti-inflammatories
  • Antitussives
  • Expectorants
  • Bronchodilators
  • Steroids (infrequently)
  • Coupage to break up mucus inside the lungs
  • Humidifiers or nebulizers can loosen the mucus,
  • Short exercise sessions may encourage the dog to cough up the mucus
  • IV fluids may be needed to prevent dehydration as well as administer medications.
  • Supplemental oxygen may be given to circulate more oxygen in the dog's body.

Dogs with pneumonia will often not want to eat, but good nutrition is important in helping them recover. Techniques such as warming up the food and offering extra smelly canned or baby foods may be used to entice a pet to eat. There are also medications to stimulate their appetite. In severe cases, a feeding tube may be put in place.

Prognosis for Dogs With Pneumonia

A dog appropriately treated for pneumonia will typically fully recover. However, your dog may be prone to relapses in the future.

How to Prevent Pneumonia

The best way to prevent a dog from developing bacterial or viral pneumonia is to vaccinate it for these diseases. Though vaccines are available for the most common causes of pneumonia, it is also recommended to keep dogs out of areas where there may be infections. Places where dogs frequent, including dog parks, dog daycare, and boarding facilities can all harbor bacteria and viruses that can cause pneumonia. If a dog is coughing or showing signs of pneumonia or another respiratory disease, other dogs should be kept away from it as well.

If inhaled irritants are the concern, keeping the air clean where a dog lives can decrease the likelihood of it causing pneumonia. Air purifiers can help keep home air clean, pet owners should never smoke in the house or by their pets, and aerosol sprays should be avoided.

Is Pneumonia Contagious to Other Animals?

Pneumonia caused by a virus or bacteria can be contagious to other animals (but not humans). Pneumonia that is caused by aspiration, an irritant, or trauma, and has inflammation but no infection, is not contagious. However, there is always a concern for an infection to develop. To be safe, if a dog is diagnosed with pneumonia it is best to keep it isolated and away from other pets.

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