Rather than trying to shut more things why don't the government try to make people stay home when they get a positive test? Only about 45% of people actually stay at home for the required period. I'd imagine thats more of an issue than pet shops.
This Joe is very much a very very very big reason why the whole system falls apart.
You need each person to isolate if you have symptoms, tell those they've been in contact to do the same, bunker in and hope not to share it.