Polycythemia vera in a dog presenting with uveitis

A 2-year-old, castrated male, mixed-breed dog presented with a 1-month history of red eyes and intermittent vomiting and a 2-week history of polyuria and polydipsia. Bilateral anterior uveitis and active chorioretinitis in the left eye were found on ophthalmic examination. Complete blood counts demonstrated evidence of an increased red blood cell mass. Thoracic and abdominal radiographs, abdominal ultrasonography, and Doppler echocardiography were unremarkable. Serum erythropoietin level was low-normal, consistent with a diagnosis of polycythemia vera. Resolution of all systemic and ocular signs occurred, and remission was achieved following phlebotomy and treatment with oral hydroxyurea.     

Leeching as initial treatment in a cat with polycythaemia vera.

Polycythaemia vera was diagnosed in a three-year-old domestic shorthaired cat referred because of seizures and a high packed cell volume (PCV). Laboratory examination revealed severe erythrocytosis (PCV 79 per cent). Diagnosis was reached by excluding causes for relative and secondary absolute polycythaemia. As phlebotomy proved impossible for initial treatment due to hyperviscosity, four leeches were used to suck blood and the PCV was consequently reduced to 64 per cent. A further 24 hours later, when bleeding at the sites of sucking had stopped, the PCV was 56 per cent. Long-term management of the condition was achieved with hydroxyurea (100 mg/cat once daily) and intermittent phlebotomy. Initial treatment using leeches in cases of polycythaemia vera is a simple, non-invasive, well tolerated and effective method where phlebotomy is not possible.     

Primary cardiac rhabdomyosarcoma in a cat

A seven-year-old domestic shorthair (DSH) cat was presented with anorexia and dyspnea. Pleural-pericardial effusion was detected with thoracic radiographs and echocardiography. Echocardiography demonstrated a large, soft-tissue mass in the right ventricular wall, protruding both into the pericardial space and into the right ventricle. Postmortem examination findings included a large mass in the right ventricular wall and multiple smaller masses on the external surface of the left ventricle and on the internal surface of the pericardium. Results of the histopathological and immunohistochemical examinations of the masses were consistent with rhabdomyosarcoma. This is the first reported case of primary cardiac rhabdomyosarcoma in the cat.     

Mammary hypertrophy in an ovariohysterectomized cat

A four year old ovariohysterectomized domestic short-haired cat under treatment for behavioral urine spraying and idiopathic alopecia developed mammary gland hypertrophy following treatment with megestrol acetate. Withdrawal of the progestin and treatment with androgen failed to cause regression of the hypertrophy. The affected mammary gland was surgically excised and recovery was uneventful.     

Multiple cardiac anomalies in a cat.

A 7-week-old domestic shorthair cat was examined because of congestive heart failure. Echocardiography and angiography were used to identify multiple cardiac anomalies. Because of the uncorrectable nature of the defects, the cat was euthanatized. Necropsy revealed persistent left vena cava, patent foramen ovale, and a right atrial/left ventricular canal. The right atrioventricular valve was replaced by a small ostium, and no chordae tendinae or papillary muscles were observed around the ostium. The pulmonary trunk originated from the right atrium. The right ventricular free wall was approximately 1 mm thick.     

Pericardial effusion and cardiac tamponade in a cat with extranodal lymphoma

A five-year-old domestic longhaired cat was evaluated for a seven-day history of worsening respiratory distress. Serum analysis for feline leukaemia virus antigen was positive. Pleural effusion was detected on thoracic radiographs and echocardiography revealed a pericardial effusion and cardiac tamponade. Cytological evaluation of the pleural and pericardial effusions showed lymphoblastic cells indicative of disseminated lymphoma. Following thoracocentesis and pericardiocentesis, the cat was treated for lymphoma using the University of Wisconsin-Madison chemotherapy protocol. The cat was sent home after three days and, at the time of writing (six months after initial presentation), was still symptom free. To the authors' knowledge, this is the first report confirming pericardial effusion and cardiac tamponade in the cat as a direct result of an extranodal lymphoma with cytological evidence of neoplastic cells in the pericardial fluid.     

Polycythemia associated with renal fibrosarcoma in a dog

A 10-year-old Beagle-type dog with intermittent vomiting and anorexia had an absolute polycythemic condition. A renal mass was detected and removed by total nephrectomy. After surgery, the hematologic values returned to normal, suggesting that the tumor was the cause of the polycythemia. The histologic diagnosis was fibrosarcoma. In dogs, secondary polycythemia has otherwise been reported with renal carcinoma and lymphosarcoma.     

Intrapericardial cyst causing cardiac tamponade in a cat

A two-year-old cat with episodic dyspnea was diagnosed with an intrapericardial cyst via two-dimensional echocardiography. The cyst directly compressed the right ventricle, resulting in cardiac tamponade. Centesis of the cyst was performed to reduce tamponade prior to surgery. At surgery, a large, fluid-filled cystic structure was found within the pericardium. The cystic structure was continuous with a pedicle of liver that passed through a small peritoneopericardial diaphragmatic hernia. Surgical resolution was achieved by median sternotomy, midline pericardotomy, resection of the cyst, and diaphragmatic herniorrhaphy.     

Hypereosinophilic syndrome with cardiac infiltration and congestive heart failure in a cat

Hypereosinophilic syndrome is an uncommon disorder in the cat. It is a heterogeneous group of conditions defined by a persistent hypereosinophilia associated with organ damage directly attributable to tissue hypereosinophilia. A seven-year-old castrated domestic shorthair cat presented to the emergency service for dyspnea. Initial physical examination identified the presence of a grade III/VI systolic left parasternal murmur with no gallop or arrhythmia. A snap N-terminal-pro hormone brain natriuretic peptide was abnormal, and a point-of-care ultrasound revealed mild pleural effusion, scant pericardial effusion, and an enlarged left atrium. There was leukemia (72.35 K/uL, reference range 4.5–15.7 K/uL) predominated by eosinophilia (33.84 K/uL; reference range 0–1.9 K/uL). On echocardiogram, there was concentric hypertrophy of the left ventricular walls with irregular endocardial borders. The left atrium was enlarged with evidence of spontaneous echogenic contrast. The mitral valve was thickened with a vegetative lesion on the anterior leaflet. Despite treatment, the patient experienced cardiopulmonary arrest, and cardiopulmonary resuscitation was unsuccessful. Complete necropsy with histopathology revealed eosinophilic infiltrates in multiple organs and the presence of a severe, acute-on-chronic, fibrinous, and eosinophilic-granulomatous endomyocarditis with mural thrombosis and marked endocardial fibrosis. This case represents an unusual presentation of the hypereosinophilic syndrome in the cat with cardiac involvement and congestive heart failure as a primary clinical sign.     

Evaluation of the renin-angiotensin system in cardiac tissues of cats with pressure-overload cardiac hypertrophy

OBJECTIVE: To clarify regulation of the renin-angiotensin (RA) system in cardiac tissues by measuring angiotensin-converting enzyme (ACE) and chymase activities in cats with pressure-overload cardiac hypertrophy. ANIMALS: 13 adult cats. PROCEDURES: Pressure-overload cardiac hypertrophy was induced by coarctation of the base of the ascending aorta in 6 cats, and 7 cats served as untreated control animals. Cats were examined before and 3 months and 2 years after surgery. Two years after surgery, cardiac hypertrophy was confirmed by echocardiography, and the blood pressure gradient was measured at the site of constriction. Cats were euthanized, and ACE and chymase activities were measured in cardiac tissues. RESULTS: Mean +/- SD pressure gradient across the aortic constriction was 63 +/- 6 mm Hg. Chymase activity predominated (75% to 85%) in the RA system of the cardiac tissues of cats. Fibrosis in the wall of the left ventricle was detected in cats with hypertrophy, and fibrosis of the papillary muscle was particularly evident. CONCLUSIONS AND CLINICAL RELEVANCE: Chronic pressure overload on the heart of cats can activate the RA system in cardiac tissues. A local increase in angiotensin II was one of the factors that sustained myocardial remodeling.     

Presumptive primary cardiac lymphoma in a cat causing pericardial effusion

We report a case of primary cardiac lymphoma in a cat, causing pericardial effusion. A 13-year-old castrated male Himalayan cat was evaluated for chronic weight loss and radiographic finding of cardiomegaly. Pericardial effusion and a heart mass were detected via echocardiography. Pericardiocentesis and ultrasound-guided fine needle aspirate of the heart mass were performed under sedation. Antemortem diagnosis of cardiac lymphoma was made based on cytology of pericardial fluid. Based on physical examination, laboratory tests and abdominal radiographs, primary cardiac lymphoma was established as the presumptive clinical diagnosis. Treatment with chemotherapeutic agents was initiated.