Suspected hepatic hydrothorax secondary to cirrhosis in a dog

Abstract An 8‐year‐old, entire, female labrador retriever presented with a 2‐week history of abdominal distension. Biochemistry identified hepatic dysfunction (elevated hepatobiliary markers, hypocholesterolaemia). Abdominal ultrasonography documented an irregular liver and a large volume of anechoic peritoneal effusion, which laboratory analysis confirmed as a protein‐poor transudate. Thoracic computed tomography identified a moderate volume of pleural effusion with a similar composition to the peritoneal fluid. Hepatic histopathology was consistent with cirrhosis secondary to chronic hepatitis and, in the absence of another cause for the pleural effusion, hydrothorax secondary to the hepatic disease was suspected. The patient was started on ciclosporin for treatment of the underlying liver disease, but developed signs consistent with disseminated intravascular coagulopathy 24 hours later and was humanely euthanased. As reported in humans, hydrothorax may therefore occur secondary to cirrhosis in dogs and should be considered as a differential diagnosis for pleural effusion in patients with advanced hepatic disease and concurrent peritoneal effusion.