Pet monitoring device

A pet monitoring system comprising:

• a sub-dermal RFID microchip implanted in a pet;
• and
• a pet monitoring device for monitoring the sub-dermal RFID microchip, the pet monitoring device comprising:
• a wearable item bearing 1 to 5 turns of electrical conductor wound circumferentially to form a wearable item resonator;
• and
• an RFID reader attachable and detachable to said wearable item, wherein said RFID reader comprises:
• a driving circuit comprising a primary inductor which inductively couples to said wearable item in response to said RFID reader being attached to said wearable item;
• a secondary inductor and a resonance capacitor which conductively couple to said wearable item in response to said RFID reader being attached to said wearable item, wherein the secondary inductor and the resonance capacitor form the wearable item resonator with said electrical conductor, wherein the wearable item resonator comprises a circuit to automatically adjust a capacitance of said resonance capacitor to compensate for a size of said wearable item;
• wherein the driving circuit is operable to drive the wearable item resonator.