Feasibility of transthoracic echocardiographic imaging in non-sedated ovine subjects using a commercial restraint device.

Transthoracic echocardiography (TTE) is a valuable non-invasive imaging research technique. In ovine models of cardiac disease, restraint for TTE often involves sedation even with currently available restraint equipment; our goal was to determine the feasibility of using a commercial restraint device, commonly known as the sheep chair, in minimizing animal stress and the need for sedation while achieving a complete TTE examination. A total of 10 healthy adult Dorset sheep were restrained in a sheep chair for TTE and observed for signs of stress. No animals displayed overt evidence of stress and none required sedation. While individual anatomic variation existed, image quality was sufficient to determine cardiac function. These observations suggest that a sheep chair is a useful aid in minimizing the need for sedation to acquire a full TTE study in ovine subjects.