The most important adverse effect of doxorubicin is cardiotoxicity, which has been reported in both human and canine medicine. However, the incidence of treatment-related cardiotoxicities after doxorubicin administration has not been fully reported among felines. We report a case of a cat that presented ventricular arrhythmia following doxorubicin administration and a literature review of cardiotoxicity in dogs and cats.

An 11-year-old domestic short-haired cat with large granular lymphocyte lymphoma presented with ventricular arrhythmia following the first administration of doxorubicin. Echocardiography showed no abnormality in heart contraction and ventricular arrhythmia had decreased for three weeks, and symptoms stopped subsequent to discontinuation of doxorubicin. The cat died on Day 584 because of the progression of the large granular lymphoma.Necropsy revealed no evidence of myocardial abnormalities, including lymphoma infiltration.

There have been a few reports of cardiotoxicity among dogs and cats. Therefore, it is necessary to investigate the cardiotoxicity of chemotherapeutic agents among canines and felines.