Humans Can Lick, Too - An Urban Legend By David Emery, About.com Guide

As told by Liz Langridge (Australia):

A young girl named Lisa was often left alone at home because her parents worked late, so they bought her a dog to protect her and keep her company. One night Lisa was awakened by a constant dripping sound. She got up and went to the kitchen to turn off the tap properly. As she was getting back into the bed she stuck her hand under the bed and the dog licked it reassuringly.

The dripping sound continued, so she went to the bathroom and turned off the tap properly in there, too. She went back to her bedroom and again stuck her hand under the bed, and again the dog licked it. But the dripping continued, so she went outside and turned off the taps out there. She came back to bed, stuck her hand under it, and the dog licked it again.

Still the dripping continued, drip, drip, drip. This time she listened and located the source of the dripping — it was coming from her cupboard. She opened the cupboard door, and there was her dog hanging upside down with its neck cut, and written on the window on the inside of the cupboard door was, "HUMANS CAN LICK TOO!!!"