Pulmonary Thromboembolism

Pulmonary thromboembolism describes a situation in which a clot forms in a blood vessel and travels to the lungs, where it blocks one or more of the arteries that carry blood through lung tissue. When this happens, parts of the lung may not receive the blood flow they need to function, and the heart may need to work harder to push blood through the remaining open vessels. Owners often arrive at this page because their dog or cat has developed sudden difficulty breathing, seems unable to settle, or is breathing rapidly even at rest. In some cases, the animal may have a known condition elsewhere in the body—such as a heart problem, a hormonal disorder, or an immune condition—that has been mentioned as carrying this risk. The signs can appear without warning and may vary depending on how much of the lung's blood supply has been affected. This page explores what patterns tend to raise concern, what may be happening in the circulation and lung tissue, how the picture is investigated when this process is suspected, and what approaches exist once the condition is identified.