What can I do, if the door doesn't recognize the implanted transponder?

In the use of the supplied RFID transponder might not be an acceptable alternative, implantation of an additional chips might be an option.

In this case, please test the chip before it is implanted. Once implanted it might be necessary to register your pet in various positions in front of the door, as the door reacts on the chip that responds first and in certain occasions the old one might still be quicker.