Non-cardiogenic thromboembolism in a Persian cat with hypertrophic cardiomyopathy

ABSTRACT

Background: Hypertrophic cardiomyopathy is the most common acquired cardiovascular disease in the feline species. A frequent complication of this cardiomyopathy is the development of cardiac congestive failure, left atrial enlargement and subsequent development of arterial thromboembolism. In a significant percentage of affected animals there is progression to congestive heart failure, resulting in cyanosis and dyspnea, often the first clinical signs reported by owners. This is a report of a 10-year-old Persian cat with hypertrophic cardiomyopathy and venous and arterial thromboembolism of non-cardiogenic origin. Case The patient was referred for cardiac evaluation, arterial thromboembolism was the suspected cause of tetraparesis. On clinical examination, a metacarpal pulse was present in all limbs; there was no cyanosis or peripheral hypothermia thus, ruling out a thromboembolic event in the limbs. Changes consistent with feline asthma and pulmonary edema were seen on radiographs, therefore hypertrophic cardiomyopathy was suspected. Treatment with enalapril (0.25 mg/kg every 12 h) for the heart condition and prednisolone (1 mg/kg every 24 h) for asthma was started. Nine days later, the patient developed mixed dyspnea (inspiratory and expiratory) and was hospitalized with signs consistent with arterial thromboembolism paralysis and cold extremities in the right and left pelvic limbs. The patient was euthanized due to the poor prognosis. Postmortem and histopathological findings revealed left ventricular concentric hypertrophy, with no valvular changes; disseminated intravascular coagulation, with thrombi in the arterial (iliac arteries, pancreatic and renal vessels) and venous (pulmonary and renal veins) beds; as well as multiple neoplastic lung masses, identified as scirrhous pulmonary adenocarcinoma, responsible for increased interstitial radiopacity. Metastasis was also identified at the tracheal bifurcation, causing radiographic changes similar to the alveolar pattern of pulmonary edema