Disclosed is a fluid dispenser, integrated into one hand piece (1). The fluid dispenser comprises a variable volume chamber, a plunger (8), a power source (5), a motor (3) and a trigger (2). The plunger translates in a linear direction relative to the chamber along a common longitudinal axis. The plunger acts to draw a volume of fluid into the chamber via a chamber inlet (13), retain the drawn fluid, and expel the fluid from the chamber via a chamber outlet (14). The power source and motor drive the translational movement of the plunger thereby causing a change in the volume of the chamber resulting in drawing or expelling fluid into or from the chamber. The trigger, when activated causes fluid to be expelled from the chamber. The hand piece may comprise a casing which at least partially encloses the power source, motor and trigger and retains the chamber, plunger and chamber inlet and outlet. The dispenser may further comprise a controller (6) operatively linked to the plunger and chamber, wherein the controller acts to control the volume expelled and/or drawn into the chamber by varying plunger translation distance, direction and/or speed. The volume expelled is based on the weigh of the subject to which the fluid dose will be applied.
