An acquired cause of pericardial effusion is pericarditis, which stems from neoplastic, immune, inflammatory, and, occasionally, infectious disease processes. (todaysveterinarynurse.com)
Collapse or profound weakness These can be symptoms of major problems such as internal bleeding (particularly a syndrome called hemoabdomen), cardiac compromise due to a condition called pericardial effusion, anaphylactic shock, certain poisonings, a glandular condition called Addison's disease, and some types of organ failure. (petsmagazine.com.sg)
Advanced imaging, such as magnetic resonance imaging, is now being used more often to diagnose the presence of cardiac masses in patients with pericardial effusion. (todaysveterinarynurse.com)