Buster used to get scared at the vet's and pee on the floor. He didn't hike his leg or anything, he just dribbled wherever he walked. It made cleanup a bit of a pain.
Ripley shocked me once in petsmart. He and I are just walking along, browsing the dog food aisles, when I notice some resistance at the end of the leash. I turn around, and I see Ripley pooing on the shelf, right next to the pro plan. I go looking around for one of those cleanup stations. Of course I am at the back of the store and the station is at the very front. I finally get to it and while I'm getting a baggie and some sanitizing stuff, Ripley pisses on the cage full of rats. One little girl looking at the rats was absolutely horrified. And oh, the dirty looks I got from the employees! You'd think a dog never peed in there before. Of course, Ripley was thrilled and quite proud of himself.
Next time we came to petsmart, Ripley stayed in my purse.
Dakota once hiked his leg on a vendor's stand at a dog show, but otherwise he's been good about holding it when we are in public.