Clinical Features, Treatment, and Outcomes of Idiopathic Pericardial Effusion in 11 Adult Dairy Cows

Abstract:

Background: Idiopathic pericardial effusion is one of the few treatable cardiac diseases in cattle; however, information regarding its clinical presentation, medical management, and prognosis remains limited.

Objective: To describe clinical signs, echocardiographic and clinicopathological findings, treatment, and outcomes in cows diagnosed with idiopathic pericardial effusion. Animals: Eleven adult dairy cows with idiopathic pericardial effusion confirmed by pericardial fluid cytology.

Methods: This retrospective case series reviewed medical records from 2008 to 2025. Signalment, clinical signs, echocardiographic and laboratory findings, treatments, and outcomes were recorded. Long-term prognosis was assessed using lactation record database.

Results: Most cows were Holstein (9/11), with a median age of 4 years (range: 2–7). Common clinical findings included bilateral jugular distension (11/11), tachycardia (8/11), and peripheral edema (6/11). Echocardiography identified anechoic pericardial effusion in all evaluated cows, with cardiac tamponade in five. Pericardial fluid was hemorrhagic in all cases, with low to moderate cellularity (median: 7.8×10⁹ cells/L; range: 3–26), elevated protein concentration (53 g/L; (35–59)), and predominance of non-degenerative neutrophils (43%; 5-65). Bovine leukosis virus (BLV) serology was positive in 6/8 tested cows, and bacteriological cultures were negative in 2 tested samples. Medical management included drainage (7/11), antimicrobial therapy (10/11), and anti-inflammatory treatment (5/11). Ten cows survived to discharge. Long-term follow-up was available for eight cows; only two completed additional lactations, both being BLV negative. Conclusion and clinical importance: Idiopathic pericardial effusion in dairy cows carries a favorable short-term prognosis but a guarded long-term outcome, particularly in BLV positive animals.