A 5-year-old FS Golden Retriever presented to VCA Mckenzie Animal Hospital for exercise intolerance. During the initial exam, a G FAST scan showed a cardiac mass, at which time Sara Hansen SDEP® Certified Clinical Sonographer of Animal Sounds NW was called in to perform a full echocardiogram to further interrogate the mass. Thank you to Sarah Brethel DVM, DACVIM (cardiology) for your comprehensive report and recommendations. Finally, thank you to Dr. Fricke for your management of this case.
HISTORY:
Clinical Exam Findings: A five-year-old FS Golden Retriever presented for reduced energy, panting, and lethargy following exercise. No history of heart murmur
Labwork – Creatinine 1.6; PCV 35% (historically 45%); BP – 100/40 mmHg
Diagnostics performed at hospital: Thoracic radiographs and ECG.
ULTRASONOGRAPHIC EXAMINATION OF THE HEART :
ECG Interpretation:
Normal sinus rhythm.
Chest Radiograph Interpretation:
The cardiac silhouette is unremarkable. There is evidence of pulmonary metastasis.
Cardiac Presentation:
The mitral valve leaflets are normal and there is trivial mitral regurgitation. There is no prolapse of the mitral valve leaflets. The left atrial size is normal. Left ventricular systolic and diastolic function is within normal limits. There is normal right atrial size with evidence of invasion into the right atrium from a mass. There is trace tricuspid regurgitation. There is no prolapse of the tricuspid valve leaflets and no evidence of pulmonary hypertension on today’s evaluation. The right ventricle subjectively appears normal in structure and function. The aortic and pulmonic valves have normal morphology and the corresponding outflow velocities are within normal limits. There is no evidence of pulmonic or aortic insufficiency. The aorta appears normal. The pulmonary artery and associated branches appear normal. There is no evidence of pleural effusion. There is mild pericardial effusion. There is a large right atrial mass with an invasion into the right auricle. There is no evidence of cardiac tamponade based upon these images.
ULTRASONOGRAPHIC FINDINGS
– Severe right atrial mass with mild pericardial effusion.
– No evidence of cardiac tamponade.
– Trace mitral regurgitation and tricuspid regurgitation.
– Pulmonary metastasis on chest radiographs.
INTERPRETATION OF THE FINDINGS & FURTHER RECOMMENDATIONS
The patient has a large mass within the right atrium and right auricle. The top differential is a hemangiosarcoma (HSA). This is also considered likely given the concern for metastasis within the lungs. Given the patient’s age, other differentials (such as a fungal infection) cannot be ruled out, but this is considered less likely. If the clients are interested in further evaluation, referral is recommended to a specialty institution for a CT scan, and also sampling of the pericardial effusion by a criticalist or cardiologist, due to the mild amount to submit for analysis and cytology. The client should be monitoring for signs of tamponade. If the patient collapses or develops ascites, then pericardiocentesis will likely be necessary. Medications such as Yunnan Baiyao can be administered. No other cardiac medications are recommended.
Patient Outcome:
The patient in this case was humanely euthanized.
General Discussion of Cardiac Neoplasia :
Evaluation of the patient included a CBC, biochemistry profile, and electrolytes as well as a gFAST scan. During the initial scan, a heart based mass was noted and the patient then received a full echocardiogram. During that echo, there was confirmation of the mass and further clarification that it was within the atrium and auricle. The most common tumor type in the heart is hemangiosarcoma. Common breeds that seem to be predisposed include the Golden Retriever, German Shepherd, Afghan Hound, Cocker Spaniel, English Setter, and Labrador Retriever. These patients often present with hemorrhagic pericardial effusion and clinical signs that are secondary to tamponade.
Other tumor types that affect the heart are chemodectomas (aortic body tumors), which seem to be more prominent in brachycephalic breeds. Like HSA, clinical signs are often related to pericardial effusion and tamponade.
Ectopic thyroid tumors, mesothelioma, and lymphoma have all been reported as well. Lymphoma is the most common tumor type in cats.
Dogs diagnosed with cardiac neoplasia tend to be middle aged to older. HSA makes up approximately 69% of cardiac tumors. In addition, cardiac HSA is considered a primary site; however, dogs with extracardiac disease can have metastasis to the cardiac tissues. In such cases, differentiating primary versus metastatic site is difficult. Up to 36% of dogs with malignant tumors had metastasis to the heart. Forty to fifty percent of canine hemangiosarcoma is located in the right atrium. Hemangiosarcoma can be found in other areas of the heart including the right ventricular free wall, the interventricular septum, and the main pulmonary artery.
Clinical signs of cardiac neoplasia often are secondary to bleeding into the pericardium and subsequent tamponade. Other clinical signs can be due to direct obstruction of blood flow by tumors. In addition, electrical activity may be disrupted by a tumor invading into the wall. In this patient, signs of low cardiac output were present: weakness with exertion or excitement.
There are few treatment options available for cardiac hemangiosarcoma. Options range from palliative treatment with periodic pericardiocentesis to chemotherapy to even surgical removal of the right atrial appendage. Screening for metastasis (especially splenic) should be performed prior to surgical intervention. In addition, a pericardectomy can be performed to reduce the likelihood of clinical signs from tamponade. However, prognosis is generally considered poor.
Citations:
- Cardiac Neoplasia (Canine). (2023, February 10). Retrieved February 14, 2025, from https://www.vin.com/members/cms/project/defaultadv1.aspx?pid=607&id=4953092
- Fossum, T. W. (2007). Small animal surgery. Mosby.
- Nelson, R. W., & Couto, C. G. (2009). Small animal internal medicine. In Elsevier eBooks. http://ci.nii.ac.jp/ncid/BA88434836
- Penninck, D., & D’Anjou, M. (2015). Atlas of small animal ultrasonography. In Wiley-Blackwell eBooks. https://ci.nii.ac.jp/ncid/BB19797248
- Porciello, F. (2020, January 1). Echocardiography in the Dog, Cat, and Horse: 2nd Edition (2020). https://www.vin.com/members/cms/project/defaultadv1.aspxpId=11229&catId=31664&id=3866788&ind=89&objTypeID=10
- Withrow and MacEwen’s small Animal Clinical Oncology. (2013). In Elsevier eBooks. https://doi.org/10.1016/c2009-0-53135-2
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