Pulmonary Thromboembolism in 29 Dogs: 1985–1995

Pulmonary thromboembolism (PTE) occurs as a complication to a number of commonly encountered clinical diseases. Antemortem recognition of this life-threatening disorder is hampered by nonspecificity of clinical signs. This retrospective study was performed to analyze clinical features, laboratory findings, imaging abnormalities, and concurrent postmortem diagnoses in 29 dogs with confirmed pulmonary embolism. A variety of clinicopathologic and radiographic abnormalities were noted but there were no pathognomonic findings for PTE. Arterial blood gas analyses were performed in 15 (52%) of 29 dogs; 12 (80%) of 15 exhibited hypoxemia and 15 (100%) of 15 had increased alveolar-arterial oxygen gradients. Response to supplemental O2 was variable and did not correlate with the presence or absence of additional pulmonary pathology on postmortem. At postmortem, 25 (86%) of 29 dogs had grossly visible emboli, 17 (59%) of 29 dogs had multiple disease processes, and 16 (55%) of 29 dogs had additional pulmonary pathology. PTE was suspected antemortem in 11 (38%) of 29 dogs. In dogs with respiratory signs consistent with PTE, the condition was a differential diagnosis in 11 of 17 animals; all had diseases previously reported to be associated with PTE. Neoplasia, systemic bacterial disease, and immune-mediated hemolytic anemia were diagnosed most frequently.