A Case Report of Chemodectoma (Heart Base Tumor) in a German Shepherd Dog From Iran (First Case)
Department of Clinical Science, Science and Research Campus of Islamic Azad University, Tehran, Iran
A nine year old male German shepherd dog was referred with abdominal distention, dyspnea and depression. In clinical examination dog was suffered from ascites, inspiration dyspnea, weakness, mild peripheral edema on limbs, unobvious lung and heart sounds, mild serous nasal discharge, anemia and cachexia.
In electrocardiography, the amplitude of all waves were decreased due to pericardial effusion, splitting of R waves and increase in S wave amplitude. Heart rate estimated 180 beat per minute, and electrical axis shifted to right (120).
Radiographic examination of the abdomen only showed large amounts of fluid in the abdomen. Sampling from ascites fluid showed it is a modified transudate. Thoracic radiographs revealed pulmonary edema and pleural and/or pericardial effusion. Cardiac silhouette was not obvious. A lot nodular densities with deferent sizes were observed in lung radiographs that showed lung metastasis.
Symptomatic treatment with furosemide (3 mg/kg), digoxin (0.01mg/kg) and captopril (0.4mg/kg) did not induce pleasure results. Thus dog was euthanatized.
On necropsy further the ascites, pleural effusion and pericardial effusion, a big tumor was seen on the base of heart that had occupied 75% of atrial volume. The walls of ventricles especially right ventricle were dilated.
Numerous metastatic tumors were seen in the lungs, liver and spleen.
Microscopic evaluation indicated that this heart base tumor is a chemodectoma.
Chemodectomas are neoplasms of chemoreceptor cells of the aortic and carotid bodies. They may appear as discrete, well encapsulated or infiltrative masses, around the great vessels and mediastinal structures.
Less commonly, there is direct cardiac extension. This tumor is predicted in brachiocephalic breeds. Although recognition related to production of precardial effusion, signs of right heart failure and radiographic findings, aortography and echocardiography, exact diagnosis in live animal requires surgical biopsy.