Look, nobody (i hope) is saying that God has really put a picture of Jesus on a dogs butt, I find the idea as repulsive as you do and i'm sure the other biblical Christians do too.
The point being made is that random patterns appear anywhere and everywhere, to some people they look like words or pictures and to others they are just doodles.
If God was going to take the time to communicate in this manner don't you think He would do a little bit more than write His name, which only has any meaning to those who understand the language it is written in, 90% of whom already believe in him?
The same goes for pictures on animals butts or buildings or whatever else, what do they prove? What could God possibly be trying to say to us by them? Think of the supreme intelligence of God, shouldn't we give him more credit than this.
His Holy Word is completely sufficent for me.