An animal access system comprising a lockable access door (11), an access door surround (29), and an implant adapted to be inserted through the outer tissue of an animal, the access door surround being provided with an induction coil operative to induce an electro-magnetic field at the access door, the induction coil being controlled by control means (21) operative to generate a control signal to lock or unlock the access door in response to a change in the induced electro-magnetic field generated as a result of the implant entering the induced electro-magnetic field, wherein the implant comprises detector means operative to detect at least one clinical parameter of the animal, the control means being operative to generate a health signal indicative of the clinical parameter, in response to a change in the induced electro-magnetic field.
