Canine Pericardial Disease: NAVLE Study Guide

Pericardial disease in dogs is one of those topics the NAVLE loves because it packs breed associations, classic clinical signs, a memorable triad, and a hands-on procedure all into one question. Know the breeds, know Beck’s triad, know your needle placement — and you’ll own this section.

What Is Pericardial Effusion?

The pericardium is a fibrous sac surrounding the heart. It normally contains a small amount of lubricating fluid — roughly 0.25 mL/kg in dogs. When that fluid accumulates beyond the pericardium’s ability to stretch, intrapericardial pressure rises and starts to compress the cardiac chambers. The result is cardiac tamponade: impaired diastolic filling, reduced stroke volume, and cardiovascular collapse.

The key concept: it’s not just the volume of fluid, it’s the rate of accumulation. A slow leak can fill the sac with 500 mL and the dog compensates. An acute bleed of 150 mL kills the dog. The pericardium needs time to stretch.