Effects of Tilmicosin Phosphate Administration on Echocardiographic Parameters in Healthy Donkeys (Equus asinus): An Experimental Study

• Administration of tilmicosin at 10 mg/kg and placebo to donkeys in a randomized crossover study.
• Echocardiographic evaluation of cardiac functions for 120 minutes after treatment.
• Tilmicosin induced transient and short-lasting changes in the cardiac function in donkeys.

The aim of this study was to evaluate the effect of tilmicosin on echocardiographic measurements in donkeys. For this purpose, placebo and tilmicosin 30% (10 mg/kg) were administered subcutaneously to clinically healthy donkeys (n = 10) in a randomized prospective crossover study. Cardiac functions were evaluated by echocardiography using a 2.5-MHz curved-linear transducer at 0, 15, 30, 60, and 120 minutes after administration. Examination was carried out at 3 to 5 intercostal spaces, and measurements were obtained at three planes of images. Tilmicosin induced a significant decrease in fractional shortening percentage (FS%) at 30 minutes after treatment (P < .05), but ejection fraction percentage (EF%) and stroke volume (SV) were decreased at 60 minutes after treatment (P < .05). However, left ventricular volume at end-systole (LVESV) was increased when compared to placebo at 30, 60, and 90 minutes after administration (P < .05). Left ventricular volume at end-diastole (LVEDV) was increased at 60 minutes after treatment (P < .05). There was a positive correlation between FS% and EF% (r = 0.89, P < .01), LVESV and left ventricle internal diameter at systole (LVIDs; r = 0.97, P < .01), and SV and LVEDV (r = 0.56, P < .01). However, there was negative correlation between LVESV and EF% (r = −0.41, P < .05), ESV and FS% (r = −0.44, P < .05), LVIDs and EF% (r = −0.43, P < .05), and LVIDs and FS% (r = −0.47, P < .05). The present results indicate that tilmicosin could induce transient and short-lasting changes of cardiac function in donkeys.