Are dogs allowed in food markets?

Court House - Are dogs allowed in food markets? Every time I am in a store I see multiple dogs in the shopping carts, not even in a container or on a blanket! Very unsanitary!! Dog owners are using the excuse that they are service dogs to board planes, stay in motel rooms, etc. I love dogs, but they should not be allowed in the shopping carts. Not everyone wants dog hair, fleas and poo on their food and clothing!