Bovine Vena Caval Thrombosis Secondary to Pneumonia – NAVLE Study Guide

Overview and Clinical Importance

Caudal vena caval thrombosis (CVCT), also known as vena caval syndrome, metastatic pneumonia, or pulmonary thromboembolism, is a severe and often fatal disease complex in cattle. It results from septic thrombi forming in the caudal vena cava, most commonly secondary to liver abscessation. The subsequent embolic showering of the pulmonary vasculature leads to embolic pneumonia, pulmonary arterial aneurysm formation, and potentially fatal pulmonary hemorrhage. This condition is of particular importance in feedlot cattle on high-grain diets and adult dairy cattle, representing a significant cause of sudden death and chronic respiratory disease in these populations.

Understanding the pathophysiology connecting ruminal acidosis, liver abscessation, vena caval thrombosis, and metastatic pneumonia is essential for NAVLE success, as this condition exemplifies the interconnection between digestive and respiratory pathology in ruminants.

Etiology and Pathogenesis

The pathogenesis of CVCT follows a well-characterized sequence known as the acidosis-rumenitis-liver abscess complex. Understanding this cascade is critical for both prevention and recognition of this disease.