The Norfolk paper has this article about a man in Arizona who wants back the dog he left with his parents three years ago, which dog has since been adopted in Virginia. One person commenting in the article notes that "that under Virginia law, a person who feeds and shelters a dog for more than five days is the dog’s owner."
Perhaps this is a reference to Va. Code 3.1-796.66, which defines "abandon" an animal as "to desert, forsake, or absolutely give up an animal without having secured another owner or custodian for the animal or by failing to provide the elements of basic care . . . for a period of five consecutive days."