Acute hemodynamic and echocardiographic responses to pimobendan versus levosimendan in a dog with decompensated dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a major cause of systolic heart failure in dogs, characterized by ventricular dilation and reduced contractility. During acute decompensation, rapid inodilator therapy is essential to stabilize hemodynamics. This case describes serial changes in non-invasive blood pressure and left ventricular systolic function observed during sequential administration of two inodilator agents via different routes on consecutive days. An Anatolian shepherd dog was presented with acute respiratory distress. Echocardiography revealed severe left ventricular dilation and systolic dysfunction, and DCM was diagnosed using established criteria. Because oral therapy was initially not tolerated, intravenous pimobendan was administered, producing a rapid but transient improvement in systolic indices and global longitudinal strain (GLS). After transition to oral pimobendan the following day, systolic function improved mildly, while GLS remained markedly reduced. Levosimendan was subsequently administered as an intravenous bolus, resulting in only minimal improvement in systolic parameters and GLS. A continuous infusion was then initiated; however, systolic measurements remained largely unchanged during infusion. Serial echocardiographic assessment, particularly GLS, documented temporal changes in myocardial function during sequential inodilator therapy. These findings represent descriptive clinical observations from the management of a single patient and should not be interpreted as evidence of comparative efficacy or superiority of one inodilator over another. Because atrial fibrillation and temporal variation in heart rate may have influenced echocardiographic measurements throughout the monitoring period, the findings should be interpreted within the methodological limitations of this sequential single-case report.