2023-04-052023-04-05202016823419https://doi.org/10.15381/rivep.v31i2.17828http://146.190.124.33/handle/123456789/5770The case of a 9-year-old Schnauzer male canine with a history of lack of appetite, lethargy and exercise intolerance is reported. Echocardiography was performed identifying pericardial effusion and a neoplastic mass in the pericardium. The patient presented cardiac tamponade, which was treated with pericardiocentesis. Once the patient was stabilized, a subphrenic partial pericardiectomy was performed, removing the neoplasticmass. The histopathological diagnosis was pleomorphic pericardial rhabdomyosarcoma. The patient had a survival time of 10 weeks. For the present case, the surgical management provided sustained clinical improvement and contributed to the diagnostic process. © 2020 Universidad Nacional Mayor de San Marcos. All rights reserved.spainfo:eu-repo/semantics/article