Echocardiographic assessment of intravenous administration of medetomidine and xylazine hydrochloride at different sedative doses in one-humped camel calves (Camelus dromedarious)

Echocardiography illustrates a convenient and noninvasive tool for measuring cardiac output (CO) changes after administration of sedative drugs, but it is unknown in camelids practice. The aim of present study was to investigate echocardiographic effects of intravenous (IV) injection of medetomidine and xylazine in camel calves. Twenty apparently healthy immature male one-humped camel calves (Camelus dromedarious) were divided into four groups (five animals in each treatment). Medetomidine and xylazine were injected into the left jugular vein at two different doses of 10.00 and 20.00 μg kg-1 and 0.20 and 0.40 mg kg-1, respectively. Effects on some selected echocardiographic parameters were recorded at different intervals, before drug administrations (baseline) and after 3, 60 and 120 min. Data were analyzed by repeated measure, ANOVA test, then relevance and significance were taken as p ≤ 0.05. Significant decrease in fractional shortening percentage (FS%), ejection fraction percentage (EF%), stroke volume (SV), heart rate (HR) and subsequent CO were noticeable 3 min after drug administration in medetomidine high dose (MH), medetomidine low dose (ML) and xylazine high dose (XH) groups (p ≤ 0.05), furthermore at this time significant decrease in left ventricular mass (LVmass) and left ventricular systolic time intervals were seen in these groups, however, in xylazine low dose (XL) group, the lowest level of most echocardiographic parameters were detectable after 60 min. High dose IV injection of medetomidine was associated with significant decrease in most echocardiographic parameters without echocardiographic arrhythmia. Although, ML and XH groups had the same effects on echocardiographic indices but the intensity and duration were less than MH group.