Check out this working dog 'Do not Pet, I'm Working' patch at Register My Service Animal. This 3" round patch identifies your dog as a working service animal.
Service Dog Patches: Standard, Custom Text, & graphics
Working Dog Do Not Pet Vest Patch for Service Dog Vest
Service Dog Please Don't Pet Me I'm Working Patch (3 Inch) Velcro Badg – karmapatch.com
My Tenant Has an Unauthorized Pet - Now What?
Do Not Pet - Im Working Service Dog Patch, Specialty Patches
3-inch Round Dog Patch: working DOG Do Not Pet Text Embroidered Patch for Working Dogs Patch for Dog Vest Dog Harness Patch
Savannah's Pet Sitting
High-Quality Tactical Service Dog Patches - Pet in Training - American Flag
Service Dog Stop No Touch Talk Eye Contact Do Not Pet Working Ignore M – KOL PET