Clinical manifestations and associated disease syndromes in dogs with cranial vena cava thrombosis: 17 cases (1989-1996).

OBJECTIVE: To characterize cranial vena cava thrombosis in dogs with regard to signalment, clinical manifestation, potential inciting causes, treatment, and outcome.
DESIGN: Retrospective study. ANIMALS: 17 dogs with a cranial vena cava thrombus. PROCEDURE: Medical and necropsy records were reviewed for signalment, potential causes of thrombus formation, diagnosis, clinicopathologic findings, treatment, and outcome.
RESULTS: A signalment predisposition was not found. Ten dogs had cranial vena cava syndrome, and 10 had a pleural effusion. Ten dogs were dyspneic, and 5 had palpable jugular thrombi. Predisposing conditions identified were presumed immune-mediated hematologic disease and corticosteroid administration (6 dogs), sepsis (6), protein-losing nephropathy (2), neoplasia (2), and cardiac disease (1). Central venous catheterization was implicated as a contributing cause. Thrombocytopenia was the most consistent clinicopathologic finding, and ultrasonography was helpful in confirming the diagnosis. Treatment varied, but 15 of the 17 dogs died or were euthanatized within 20 days of clinical manifestation of the thrombus. At necropsy, thrombi were found in other organs, mainly the right atrium, jugular veins, and pulmonary arteries. CLINICAL IMPLICATIONS: Prognosis is poor for dogs with cranial vena cava thrombosis associated with clinical signs. Use of central venous catheters should be avoided in dogs with predisposing diseases such as immune-mediated disease, sepsis, protein-losing nephropathy, neoplasia, and cardiac disease.