I have a "Fireman - Rescue my Dog!" sticker on front and rear windows. Happens to be true in my case but also informs potential intruders that they will be greeted by a carnivore with large fangs.
Please do not endanger a Firefighter by placing a fictitious “Pet Rescue” sticker just to increase home security. While the same could be said for “fake” bowls, toys, etc. the “Rescue My Dog” sticker is crossing the line in my opinion.
Pete