Case Description—A 10-year-old spayed female Corgi mix was examined for a 3-week history of lethargy and weight gain.
Clinical Findings—Physical examination findings included muffled heart sounds and a distended abdomen with a fluid wave on ballottement. Thoracic radiography revealed a globoid cardiac silhouette, and thoracic ultrasonography indicated pericardial effusion and a pedunculated mass originating from the right auricle.
Treatment and Outcome—Initial treatment consisted of pericardiocentesis. One week later, thoracoscopic right atrial mass resection was performed. No surgical complications were noted, and the dog was discharged approximately 28 hours after surgery. Results of histologic examination of the mass indicated a grade 2 hemangiosarcoma with incomplete margins. Treatment with doxorubicin was initiated 35 days after surgery. The dog survived for 177 days after mass resection, when it was euthanized because of complications related to metastatic disease.
Clinical Relevance—Findings suggested that thoracoscopic right atrial mass removal combined with adjunct doxorubicin treatment may be a viable alternative to thoracotomy in dogs with right atrial masses.