Aspiration Pneumonia

Aspiration pneumonia describes inflammation and infection in the lungs that develops when material from the mouth, throat, or stomach enters the airways instead of travelling down the oesophagus. This can happen during vomiting, regurgitation, or when swallowing mechanisms are impaired. The inhaled material may carry bacteria, stomach acid, or food particles that irritate or damage delicate lung tissue. Owners often notice sudden breathing changes—rapid, laboured breathing, coughing, or reluctance to lie down—sometimes hours or days after an episode of vomiting or known difficulty swallowing. In other cases, the aspiration event itself may not have been witnessed, and the first sign is simply that a dog or cat has become quieter, is eating less, or seems uncomfortable when breathing. This page explores the patterns that may raise concern, what happens in the airways and lungs when aspiration occurs, how the condition is investigated through examination and imaging, and the range of approaches used in different situations.