If you own a pet store, would you let visitors take photos of your pets?

Take puppies and kitties out from their cage for photos is a different story though. I wouldn't like it if everyone try to do it without buying them. Your point is also right on the vaccination.

Most pet stores I had visited so far do not sell dogs and cats. Their live pets are limited to fish, birds, reptiles, mostly those don't leave their tanks and cages in the pet store unless a sale is made. Taking a photo of what's in the fish tank is totally fine in my opinion. Birds, might get scared if the flash is on. Reptiles, they barely move even the flash is on.