Understanding pericardial effusion in dogs — fluid around the heart that causes life-threatening cardiac tamponade.
Pericardial effusion causes acute welfare impairment through cardiac tamponade. As fluid accumulates around the heart, filling pressure rises and cardiac output falls. Dogs show exercise intolerance, laboured breathing, weakness, and collapse. The acute presentation can be frightening — dogs may collapse suddenly with pale gums and a rapid, weak pulse.
The underlying cause significantly affects prognosis and welfare planning. Haemangiosarcoma — the most common malignant cause — carries a poor prognosis with median survival of 1-4 months even with treatment. Idiopathic pericardial effusion, by contrast, has a much better prognosis with pericardiectomy often providing long-term resolution.
Pericardiocentesis provides immediate dramatic relief — dogs often recover strikingly quickly as cardiac output is restored. The procedure carries some risk but is generally well-tolerated. Pericardiectomy (surgical removal of part of the pericardium) prevents recurrence and is the recommended treatment for recurrent idiopathic effusion.