There are many different types of pneumonia in dogs including bacterial, aspiration, and fungal. Bacterial pneumonia, in which bacteria causes the condition, is the most common and there are two different types – bronchopneumonia and pneumonia. Bronchopneumonia is when both the lungs and the airways, including the bronchi and bronchioles, are affected while pneumonia refers to an inflammation of the lungs or lower respiratory tract. While there are slight differences between these two types of pneumonia in dogs, the terms are often used interchangeably.

Causes of Pneumonia in Dogs

Pneumonia occurs when the lungs and airways become inflamed due to a response to injury, irritation, or infection. Bacterial infection is the most common cause of pneumonia, with the most common species being Bordetella, bronchiseptica, Streptococcus zooepidemicus, Pasteurella multocida, Pseudomonas aeruginosa, Klebsiella pneumoniae, E. coli and Mycoplasma.

Of these types of bacteria, Bordetella bronchiseptica is the only one that’s contagious; and it spreads very easily to other dogs. It will begin as a kennel cough, which infects the trachea and bronchi. Over time it will spread deeper into the lungs, causing full blown pneumonia, especially in older or younger dogs, or dogs that have a compromised immune system.

Bacterial pneumonia can also be a secondary infection, meaning that it’s an infection caused by another condition or infection that was present first. This is sometimes the case with viral infections such as parainfluenza or canine adenovirus type-2.

In some cases environmental factors can also cause pneumonia. These include things such as tobacco, smoke, smog, or other inhaled pollutants. When dogs are surrounded by these environmental factors, they can become predisposed to bacterial pneumonia.

Risk Factors for Pneumonia in Dogs

In addition to environmental factors, there are other factors that can put certain dogs at risk. Primarily that is any disease or condition that affects the respiratory tract or that cause difficulty swallowing or problems with regurgitation. Some of the most common conditions that are known to put dogs at particular risk for developing pneumonia are:

• Laryngeal paralysis
• Megaesophagus
• Cleft palate
• Chronic vomiting
• Altered states of consciousness
• Tumors of the respiratory system
• Immune system diseases
• Kidney failure
• Uncontrolled diabetes
• Cushing’s disease
• Addison’s disease

Diagnosing Pneumonia in Dogs

Before diagnosing pneumonia, a vet will consider the symptoms that are present and perform a full physical exam. During this examination, the vet will listen to the dog’s chest with a stethoscope. If abnormal breathing is heard, the vet will run a number of other diagnostic tests to rule out other conditions, and to check the lungs, bronchioles, and airways.

These tests include:

• A CBC and biochemistry profile: This will include blood and fecal tests that will eliminate the possibility of heartworm, lungworm, or other parasites. Blood tests may also be performed to determine if serious metabolic diseases may be the cause of the symptoms.
• X-rays: These will be taken so that the lungs may be analyzed and any changes in the lung’s characteristics can be detected. X-rays of the heart may also be taken to rule out heart disease.
• Cytology: This is a procedure that is done while the dog is under anesthesia. During this procedure a bronchoscope will be inserted into the airways so that samples of the cells within the lining of the bronchioles and bronchi can be collected and studied for bacterial culture and sensitivity testing. These samples can also be taken through a tracheal lavage, in which a small amount of saline fluid is flushed into the airways and then collected to look for mucus and cells from within the lung tissue.

Treating Pneumonia in Dogs

The treatment of your dog’s pneumonia will depend on the results of the culture and sensitivity tests that were taken during the diagnosis process. The type of bacteria that is causing the infection, and ultimately the pneumonia, will determine which type of antibiotic will best treat it. However, the results of these tests most likely won’t be available right away and so, the vet will likely begin a course of broad spectrum antibiotics that will still help to combat the infection.

In addition to the antibiotics, the vet may also prescribe bronchodilators, expectorants, or other medications that will help keep the symptoms under control and make the dog more comfortable throughout their recovery. These medications may be required for an extended period of time, depending on how serious the condition is and the specific type of infection.

In addition to medication, there are things that can be done at home to help a dog suffering from pneumonia. These include brief exercise sessions daily to help loosen mucus and promote coughing it out. Keeping the dog in a bathroom with a warm shower running for about 15 minutes can also be done several times a day to help loosen and excrete mucus.

If a dog’s condition is very serious and they’re having a lot of trouble breathing, they may need to be hospitalized for oxygen therapy and/or intravenous fluids and medications.

Prognosis for Dogs With Pneumonia

Typically bacterial pneumonia is very easily treated with antibiotics and medication, giving most dogs a very good prognosis for going back to their normal happy lives just a few weeks after developing pneumonia.

If the pneumonia is very severe, the prognosis will depend on the predisposing factors that placed the dog at risk for pneumonia in the first place. If these factors cannot be resolved, recurrent infections may occur. The prognosis for pneumonia in older and younger dogs, or dogs with immunodeficiency diseases, can be guarded.