Sounds like 1 good samaritan turned them over to animal control - maybe because they were found loose, (they escaped the owner's yard?) And someone else saw those two as an opportunity.
I shake my head, because I am so hypervigilante about my own dog's whereabouts and safety. Even if i ever live in a house, he will not be going outside without supervision from me. Because of my fears of him escaping and getting lost or stolen from unscrupulous people.