A delivery device comprises, a collar device (130) for wearing on an animal, said collar device (130) comprising a dosing chamber for delivering a substance therefrom； a probe (132) protruding from said collar (130) towards skin of said animal an actuator (10) for causing said substance to be delivered from said dosing chamber through said probe (132)； a controller (10) for controlling delivery of said substance from said dosing chamber； and a skin contact sensor (134) for sensing that a collar is properly positioned on the animal, whereby said substance is administered only when the collar is on the animal.
