January 15, 2020 Internal Medicine

Common Causes of Pneumonia in Pets

An x-ray showing pneumonia in a dog's lung

Common Causes of Pneumonia in Pets

The sudden death from pneumonia of ESPN reporter Edward Aschoff, was widely reported. The shocking loss of this apparently healthy young man has left everyone on edge about pneumonia, including pet owners’ concern about cold weather as a cause. During the winter months, pet owners are often concerned their pet might contract pneumonia after getting chilled while they are outside “doing their business.”

In medical parlance, pneumonia means inflammation in one or both lungs. Pets suffering from pneumonia will breathe quickly, cough, maybe have a fever and generally act lethargic. An x-ray is a useful diagnostic tool, but sometimes blood tests, CT scans or bronchoscopy are necessary to make a diagnosis of pneumonia.

Usually pneumonia has a qualifying term that precedes it to describe the type of pneumonia and give clues to its cause. In this blogpost I will describe some of the more common forms of pneumonia we see in pets.

Infectious Pneumonia

The most easily comprehended form of pneumonia is infectious: pneumonia caused by a microorganism. In young dogs, distemper virus can cause pneumonia, and in young cats, feline herpes virus may be responsible for a case of pneumonia. Canine influenza infection can also lead to pneumonia. In certain parts of the United States, fungal infections with Blastomyces or Histoplasma organisms result in pneumonia. Parasitic pneumonia results from infections with lung flukes and lungworms.

Bacterial Pneumonia

Even though pneumonia caused by bacteria is infectious, I’m separating it from other infectious pneumonias because bacterial pneumonia is often secondary to a viral or parasitic pneumonia or another respiratory insult like smoke inhalation or near drowning. Dogs with brachycephalic airway syndrome are at risk for developing bacterial pneumonia because their respiratory tract is abnormally shaped and lacks some of the normal defenses of dogs with longer noses. Watch this space next week for a blogpost on brachycephalic airway syndrome.

Noninfectious Pneumonia

Aspiration (inhalation) of stomach contents into the lungs is significant cause of pneumonia. Vomiting is the major risk factor for aspiration of stomach contents, but bloat, anesthesia, megaesophagus and force feeding can result in aspiration pneumonia. The cause of pneumonia in these situations is irritation of the delicate lung tissue by the acidic stomach contents.  Other irritants leading to pneumonia include smoke inhalation and aspiration of lake or ocean water during a swimming accident.

While any changes in your pet’s breathing pattern is a cause for concern, notice that catching a chill does not make my list of common causes of pneumonia so keep up that New Year’s resolution to get your pet and yourself more exercise!

Tags: bacterial pneumonia, infectious pneumonia, noninfectious pneumonia, pneumonia, pneumonia in cats, pneumonia in dogs,

Related Posts