The ultrasonograph has a gel dispensing device connected or integrated to a signal transmitting or receiving probe and provided with a gel tank for transmitting ultrasonic waves for purpose of medical, paramedical or veterinary procedures. Gel provoking from the tank integrated to the probe emerges through an orifice near a signal transmission and reception window of the probe. The tank is constituted by a hermetic and sterile flexible pad connected by conveying units e.g. tubes (8), to a peristaltic pump (9) that is hermetically connected to the probe.