Is it OK to pet a guide dog?
It's always best to ask the guide dog's owner first.
Guide dogs are working dogs that help their owners to find their way around. Petting the dog (however tempting), while it's in its harness and helping its owner get around, distracts the dog from its work and could put its owner at risk of danger or delay to an essential journey.
Guide dog owners are used to their dogs getting a lot of attention from the public but, just like you and me, they may not always have time to stop or they may need their guide dog to focus more in unfamiliar areas, so don't be offended if they ask you not to pet their dog.
Sometimes when a guide dog is out with its owner in a park or similar, the owner may remove the dog's harness and let it play freely, but it's still best to ask if you can pet the dog before you do.