It's not common for people to take their dog into the pet store in Canberra actually. And they definitely don't encourage it, though in most places they wouldn't kick you out either, I think.
We used to have this absolutely awesome drive through pet store close to where I lived. It was a huge shed built on one of the platforms of the old railway station and you just drove your car in! It was more for bulk food and stuff, but I just loved taking my dog there.
The other pet stores I know are quite cramped, so I do feel like taking a bull into a china shop when I take Banjo in.