A few nice service animal images I found:
"Service Turtle" in hand.
Image by http://www.petsadviser.com
You may use this photo as long as you link to our website, petsadviser.com - thanks! Yes, you can delete the text on the shell if you want, or adapt this however you see fit, but please link to our website.
Service Animal
Image by tom.arthur
As seen at the Lions Surf City Splash in Huntington Beach, CA