Documents You May Need When Transferring a Dog to a New Owner
https://caninehomeguide.birchreport.com/posts/documents-you-may-need-when-transferring-a-dog-to-a-new-owner
When transferring your dog to a new owner, you'll need its medical records, including vaccination history and spay/neuter certificate. The microchip registration should be updated, and any registration papers from your city or county must be transferred. Also gather proof of purchase or adoption, plus any behavioral notes and feeding schedules to help the new owner care for your dog properly.