Pleural effusions in the dog. Etiology, Pathogenesis, Diagnosis and Treatment

Accumulation of fluid (pleural effusion) in the pleural space of dogs is a relatively common clinical entity in the everyday practice. These can result from variable causes, such as right-sided heart failure, pericardial disease, hypoalbouminemia, neoplasia, heartworm disease, diaphragmatic hernia, bleeding disorders, traumatic or idiopathic causes. Diagnosis is based on history, clinical findings, laboratory tests, thoracocentesis, thoracic radiography and/or ultrasonography. Therapeutic approach depends on the etiology and the clinical condition of the affected dog. In dogs presented with severe respiratory distress, and after the confirmation of pleural effusion with thoracic radiography, thoracocentesis is performed to stabilize the animal's condition. If indicated, surgical management is attempted. Conservative therapy includes intravenous fluid and electrolyte replacement, antibiotics administration and chest tube placement in refractory cases. Moreover, pleurodesis may be indicated in chronic relapsing cases.