I understand that not all christians take issue with this. I will say most of the time I have no problem with Nim, however the difference in this case is that it is not an extreme that we all see as rediculous, but a reality that is far too common in modern Christianity.
I know from personal experience on a "Christian" campus that far too often Christians make light of bashing fellow believers or others about their beliefs. Maybe it's something my circumstances have made me sensative to, and I realize not everyone will find the same things humorous. Perhaps then, instead of not using the notion again, the next time you should point out somethings along the lines of how Christian speech is to be edifying.
Jeff, all in all, I like prayer pups. I by no means want to discourage your work and the ministry that comes from it.