Pulmonary thromboembolism in cats: 29 cases (1987-1997)

OBJECTIVE: To determine clinical signs, clinicopathologic abnormalities, radiographic findings, histologic abnormalities, and predisposing factors or diseases in cats with pulmonary thromboembolism (PTE). DESIGN: Retrospective study. ANIMALS: 29 cats in which PTE was confirmed at necropsy. PROCEDURE: Information on signalment, body weight, history, results of physical examination, results of CBC and serum biochemical analyses, whether PTE was suspected prior to death, type of indwelling venous catheter and duration of venous catheterization, results of thoracic radiography, and whether cats had any concurrent diseases was obtained from medical records. RESULTS: PTE was identified in cats of various ages (median, 8.7 years), weights (median, 4.1 kg 9 lb]), and breeds. The most common owner-reported problems included lethargy (17 cats), anorexia (14), weight loss (10), and difficulty breathing (8); physical abnormalities included lethargy (21), tachypnea or dyspnea (16), and dehydration (13). Clinicopathologic abnormalities reflected concurrent or underlying diseases. Common radiographic abnormalities included pulmonary vessel abnormalities (11), pleural effusion (8), and peripheral noncircumscribed consolidations (6). Underlying or predisposing conditions, including cardiac disease (12), neoplasia (10), corticosteroid administration (8), disseminated intravascular coagulation (5), protein-losing nephropathy (4) or enteropathy (4), immune-mediated hemolytic anemia (2), and sepsis (2) were identified in all cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that PTE can develop in cats of any age, sex, or breed. Because PTE is a serious, potentially life-threatening disease, it should be suspected in cats with thoracic radiographic changes suggestive of uneven distribution of blood flow between lung lobes, especially in cats that have predisposing factors or diseases.