You will probably have to find a vet or a "dog-catcher" with a 125-134 kHz scanner.
Google "keyword" ... rfid animal tracing chip which frequency
2) Disadvantages of Microchips
Quote : Some scanners do not read chips from other manufacturers.
4) My technical understanding of this : The scanner is sending out a
radiosignal activating the chip and thereby getting response back.
Regards and good luck !