Best Reddit comment:

I've heard stories of this making dogs go crazy in the long term. One guy said his dog got super anxious in his house because it would constantly search for the laser thinking it was still hiding somewhere. Probably doesn't happen to all dogs, but I wouldn't try it with mine, that's for sure.

Why laser pointers are bad for dogs:

400 Reddit comments:

http://reddit.com/r/videos/comments/2p1yet/laser_mounted_to_dogs_collar_hilarity_ensues_103/