Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Pneumonia, Pleuropneumonia & Pleuritis, Generally

Synonyms: Shipping Fever, Transit Fever


Pleuropneumonia is a lung infection (pneumonia), combined with an infection of the pleural cavity (pleruitis). It is also called "Shipping Fever" because its development is often associated with the stress of long-distance trailering.

Pleuropneumonia is uncommon in horses but potentially a serious or fatal problem that must be diagnosed and treated early and correctly. It is a bacterial (rarely fungal) infection of the lung that may extend into the space around it (the pleural cavity). Fluid accumulates in this space as part of the inflammatory process (pleural effusion).

Infection can be difficult to control and becomes more difficult the longer that infection persists. In time, fibrin strands and clots (an inflammatory product) fill the space and isolate pockets of fluid. Clearing this fluid is difficult and expensive, and requires the use of thoracic drains and flushing.

Pneumonia may start as respiratory tract infection that progresses deeper into the lungs or may start without an obvious cause. Aspiration pneumonia refers to a situation in which foreign material and bacteria is inhaled or gains access to the lungs.

my vet's role


Fair to guarded, depending upon the nature of the infection, the presence of fluid in the chest (pleural effusion), and how long the infection progresses before effective treatment is started. Laminitis commonly results from a severe bacterial pleuropneumonia.

my role


I might observe

You might make these observations when a horse has this condition.

Very Common
Less Common
more observations

further reading & resources

Related References:

Cha ML, Lais RR, Costa MV: Inhalation Therapy in Horses: In Veterinary Clinics of North America.

Author: Doug Thal DVM Dipl. ABVP