Assessment of the Cardiac Functions Using Full Conventional Echocardiography with Tissue Doppler Imaging before and after Xylazine Sedation in Male Shiba Goats

SIMPLE SUMMARY: Echocardiography, as a feasible tool used to evaluate the cardiac functions, is relatively expanded in the literature of goat’s research because of being a reproducible animal exemplary for cardiovascular research. However, previous studies do not fully describe the full echocardiographic protocol including tissue Doppler imaging (TDI) in goats, the same as used in pet animals, and it was rather mainly focusing on females than males despite its importance for studying the flow dynamics in ruminants. The clinical utility of echocardiography in farm animal practice is still limited and mainly utilized for research purposes. Consequently, the culling strategy of diseased animals suffering from cardiac disorders is usually prioritized more than treatment because of lacking the precise diagnosis of the problem. Breed-specific variations in the echocardiographic measurements may occur and there are no previous study documents the echocardiographic interval parameters in Shiba goats, a native breed in Japan. In the current study, we investigated the feasibility of the full conventional echocardiography protocol as used in companion animal practice and reported for the first time the TDI indices in male goats to provide valuable reference data that can be used for either research or clinical cardiology application in goats. We further highlighted the echocardiographic changes after sedation with xylazine, a common anesthetic medication used in ruminants, as a guide to veterinarians under field conditions. ABSTRACT: The present study aimed to provide a complete conventional echocardiographic protocol in adult male Shiba goats by using two-dimensional, M-mode, Pulsed Wave Doppler, and tissue Doppler imaging (TDI) echocardiography, and to study concomitantly xylazine-induced alteration of cardiac functions in a highly sensitive species. For this purpose, 12 male Shiba goats were included and complete conventional echocardiography from the standard right and left parasternal views was carried to report the echocardiographic data in male Shiba goats, and also before and after xylazine (Pre-Xyl and Post-Xyl) administration (0.05 mg/IM/kg). Results revealed that the full echocardiographic protocol was feasible in all goats through different cardiac windows and good Doppler alignment was achieved with non-significant variability for assessment of the left ventricular dimensions, trans-pulmonary, trans-aortic, and trans-mitral blood flow. The TDI, which was not reported previously in goats, was successfully assessed from the standard left apical view and showed distinct systolic and diastolic patterns. Xylazine administration was found to significantly reduce heart rate, fractional shortening, and cardiac output as well as the Doppler hemodynamic parameters of the pulmonary artery, aortic and mitral inflows (p < 0.05). For TDI, the Post-Xyl group revealed a significant decrease in the myocardial velocities of the septal and lateral wall of the left ventricle. The present study provides, for the first time, complete data of conventional echocardiography in male goats using the full protocol, which is routinely used in pet’s practice. Further, we illustrate in-depth the adverse effect of short-term sedative, xylazine, as used under field conditions and emphasize a simultaneous reduction in both systolic and diastolic cardiac function in goats based on full echocardiography assessment of the heart.