Imperforated cor triatriatum dexter in a dog with concurrent caudal vena cava wall mineralization

Background: Cor triatriatum dexter (CTD) is a rare congenital cardiac malformation with various manifestations and has been sporadically described in dogs. Clinically the dogs present with nonspecific signs of right heart failure or Budd-Chiari-like syndrome. Other associated concurrent cardiovascular anomalies are commonly reported. Diagnosis and full characterization of this complex malformation requires careful investigation and often a multimodal imaging approach. Case presentation: A 10-week-old, male intact, Golden Retriever was presented with clinical signs of stunted growth, anorexia, and progressive ascites. CTD imperforate with sole separation of the caudal vena cava (CdVC) and concurrent venous wall mineralization was conjointly diagnosed and fully characterized by echocardiography, nonselective angiography, computed tomography angiography and cardiac magnetic resonance imaging (MRI). This was successfully treated surgically and the dog returned to normal activity. Conclusion: To the author's knowledge, this is the first case of CTD imperforate separating the CdVC from the right atrium (RA) with presumed secondary CdCV wall and hepatic parenchyma mineralization reported in a dog. CTD is an important and potentially correctable cause for the development of ascites in a young puppy. Accurate diagnosis of this complex cardiac anomaly is important for selection of the most appropriate curative treatment option.