Here is a really cute sign that reads " WARNING The dog will let you in but you ain't getting out for the doberman lovers
designed and hand made by me

I can customize to suit your needs

It is high quality vinyl on an aluminum back ground

other signs can also be ordered to read

Beware of Rooster
Beware of geese
Beware of Donkey
Beware of Goat
Beware of wife
Beware of Children
Beware of dog poo
Beware of cat poo
Beware of Doggie bombs etc

use your imagination