Woah, wait a second, backup here. The last time I heard this mumbo-jumbo was back when I was living in Michigan, and thought it was shit back then. First of all, we are talking about cats and dogs, and cows here, not people. Though some nutter parents are considering microchipping their kids, creepy if you ask me (control freak much?) How does this all relate to religion? Well those microchips are the mark of the beast. Yup you got it, the Devil works through silicon! Who knew...?
Here's the two relevant passages, forgive me for using two different Bible versions, but since it's all the word of God, I suppose it doesn't matter of they were edited by King James or not.
And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name. Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six.
-Rev. 13:17-18 (KJB)
He also forced everyone, small and great, rich and poor, free and slave, to receive a mark on his right hand or on his forehead, so that no one could buy or sell unless he had the mark, which is the name of the beast or the number of his name.
– Rev. 13:16-17 (NIV)
Left hand everyone, that's the key. You can do whatever you want to your left hand, bar code it, microchip it, tatoo 666 all over it, and it doesn't matter. Right hand only, oh and watch the forehead too...these passages just go to show how bonkers this whole line of reasoning really is. Now it may be that this whole thing is metaphorical, as religion really should be received. Perhaps it is some kind of a spiritual marking that it is referring to, and the whole forehead/righthand/lefthand thing is just some made up bullshit passed on over the years.
Furthermore, the kind of nutters that believe this crap are the same nutters who think that kitties have no soul, and are simply beasts put on earth for us humans. In that case, she should feel free to microchip her kitty anyway, who cares if it is a minion of the devil?