Pneumonia in Dogs: Types, Clinical Signs, Treatment & Prevention

Similar to humans, dogs are susceptible to lung diseases, but it can be hard to notice lung problems, such as pneumonia, in dogs if you don't know what you are looking for. Pneumonia is a condition that affects the lungs and airways, and it can cause coughing and difficulty breathing. Different types of pneumonia, such as aspiration pneumonia, can affect your pup in different ways. Learn more about the clinical signs and treatment options should your dog contract pneumonia.

Types of Dog Pneumonia

Anything that causes inflammation in the lungs and airways can cause pneumonia. This may include accidentally inhaling food contaminated with bacteria, or even upper-respiratory infections, accidental inhalation of grass seeds, fungal infections and tick-borne infections. Some of the most common types of pneumonia include:

Aspiration Pneumonia

Aspiration pneumonia in dogs is one of the most common types of pneumonia. It occurs when food or vomit contaminated with bacteria is accidentally inhaled or "aspirated" into the lungs. Aspiration pneumonia can occur in dogs who have laryngeal paralysis, a cleft palate, megaesophagus, acid reflux, dogs who have seizures, are in a coma or under anesthesia.

Infectious Pneumonia

There are a wide variety of infectious organisms that can ultimately result in pneumonia. A few of the more common infectious causes include viruses, such as the influenza or distemper viruses, both of which can primarily infect lung tissue and can sufficiently damage the lungs in a way that allows secondary bacterial infections to develop. Bacteria may also be the primary cause of pneumonia with certain diseases such as Bordetella, the bacteria that causes kennel cough. As a pet parent, it's very important to be aware of these three infectious causes of pneumonia as well as how they are extremely contagious to other dogs. Dogs may also develop bacterial pneumonia by inhaling foreign objects that become lodged in the lung tissue. Most commonly, this occurs with things such as grass seeds or foxtail awns and may be particularly problematic in certain areas of the country, such as the Midwest and west coast, where foxtail weeds are very common.

Another major group of infectious causes of pneumonia in dogs include fungal pneumonia, which occurs when fungus is inhaled from contaminated soil or plant debris and colonizes the lungs. Blastomyces, Histoplasma, Cryptococcus and Coccidioides immitis are the main culprits in fungal pneumonia and where you live in the country will influence which fungi pose the biggest threat to your pup. For example, Blastomyces tends to be more common around some of the Great Lakes states (Michigan, Wisconsin, Illinois) and the Ohio River Valley, whereas Coccidioides tends to show up more in the dry, arid climates of the southwest. Although fungal causes of pneumonia are not directly transmissible between people and dogs (or between dogs), it's important to remember that these fungal spores live in the environment and that many of the same fungi that cause pneumonia in dogs can infect people as well.

Lastly, although much less common, there are certain types of parasites and protozoa that can cause pneumonia as well. These more commonly affect young puppies or animals that have a compromised immune system from medications or other diseases such as cancer, severe kidney disease, diabetes mellitus or Cushing's disease. In particular, there is a rare type of protozoal pneumonia to which Dachshunds and Cavalier King Charles Spaniels are particularly susceptible due to an inherited immune system defect sometimes seen in these breeds.

Eosinophilic Pneumonia

Another type of pneumonia is called eosinophilic pneumonia, more commonly seen in certain breeds such as Rottweilers. Although this disease process is not well understood, it's believed to occur as part of an allergic response to things including pollen, fungal spores and heartworms. Other respiratory parasites have also been reported to cause allergic or eosinophilic pneumonia, as well as tick-borne diseases, including Rocky Mountain spotted fever and ehrlichiosis.