I might convince my local vetrenarian to implant that RFID-chip in my hand if I'm sure it will work. If the Paralax doesn't work please share your knowledge on how to use something else!
It may or may not be the same interface as the Parallax.
Here (http://iteadstudio.com/produce/134-2khz-rfid-reader-module-rdm660/) they say:
"It’s similar to RDM630 125kHz RFID reader module , nearly the same pins and the same output protocol, user just need to read the UART serial port that you can get the card / tag ID."
In this article: http://iteadstudio.com/produce/play-rdm630-with-arduino/ they give some example code for Arduino. Looks like they just read 11 bytes and display bytes 4 through 11 (8 ascii characters representing hexadecimal digits) on an LCD. The hexadecimal, when converted to decimal gave them the decimal number shown on the tag. There are probably framing characters like on the Parallax so it would be good to check for those. You could also check the checksum to be sure the read was clean.
I wrote about this on my blog last month, 125Khz RFID Module RDM630, and included sample code. It is a very similar module, so this may help you.
Some of the examples out there use the hardware UART on the Arduino, which I am not a fan of because I like to have the serial monitor free for debugging.
Alternately, the sniffer nano does look pretty cool. I've been meaning to check one of those out.