Vena Caval Thrombosis and Metastatic Pneumonia in Cattle

Vena caval thrombosis and metastatic pneumonia is associated with multifocal abscesses in the lung as the result of septic embolism of the pulmonary arterial vascular system arising from septic thrombi in the caudal vena cava. The most common cause of vena caval thrombosis is ruminal acidosis leading to rumenitis and subsequent liver abscessation, which may result in a thrombus in the caudal vena cava if the vessel wall is infiltrated by the abscess. Bacteria most frequently involved include Fusobacterium necrophorum, Trueperella pyogenes, staphylococci, streptococci, and Escherichia coli.

The condition usually occurs in adult dairy cattle or in feedlot cattle on high-carbohydrate diets. Presenting signs can be acute, manifested by respiratory distress, or chronic, manifested by weight loss and chronic coughing. A common presentation is tachypnea, tachycardia, hemic murmurs, coughing, pale mucous membranes, increased lung sounds, hemoptysis, and epistaxis. Pyrexia and melena may also be present. The case fatality rate is essentially 100%.

Because of the poor prognosis, treatment is not indicated. If attempted, treatment includes antibiotics and supportive therapy. Control efforts should focus on reducing the incidence of ruminal acidosis, which can result in rumenitis and subsequent formation of liver abscesses.