Creating a contract for my dog?

so for a temporary amount of time i have to send my dog to stay with my grandma. my mom is "sick" and hurts her. so to keep her safe im sending her to stay there, but i dont like my grandma. i know she will take care of Italia but i want my dog back. and i want her to be taken care of the right way, ie: doesnt get her diet changed. i want to make some type of document with things my grandma can't do. i hope you understand. i need some help on what to do.