I like the strong presence of the letter "S" - it can later be a standalone iconic element.
Can you please consider some variations of the red "S" to incorporate an eye in the upper part of the white hole area, or a sword somehow so that it looks first and foremost as an "S" and then has some secondary elements to the letter upon second look. Does that make any sense?
This design will ultimately be on black tshirts, and other things worn by law enforcement and military guys so it needs to continue with a masculine theme but reference safeguarding children, etc.
At first I didn't get the hair at the top -- when I think of sheepdogs I think of a different breed, that has short hair -- but after doing my own research, I now realize you were referencing Old English Sheepdogs. As you can see there are a wide variety...and some are as vicious as the day is long...but in keeping their flock safe and "directed."
http://en.wikipedia.org/wiki/Sheep_dog