The main problem I encountered in the shop was following shop etiquette. No one explained to me that you had to buy before you eat. It wasn't obvious. I mean if you put food on open display at mouth height, you should expect me to eat some of it. I had a similar problem in the newsagents with the newspapers being on the lowest shelf. Apparently you need to buy them too before soiling them. I never saw any prohibition notices. I think that's why most shops only allow entry to guide dogs. They've obviously read the guide on how to behave in shops.
We were asked to leave the pet shop but only after my master had paid for my snacking. We're not allowed back. I hope I managed to 'contaminate' enough food (their word not mine) to keep me going till he finds me another food source. I don't want to end up starving. Speaking of which, somewhere in my genetics, I'm told, I've got a bit of whippet. I can't see it myself. I met three muzzled whippets at the campsite and they just looked anorexic. I love food too much to look that thin. Maybe the owner forgets to remove their muzzles at meals times. No wonder they're bad tempered.