Thank you for your question
My name is ***** ***** I shall do my best to help you although I fear that the news that I have is not good.
However strongly we feel about our pets the law simply views them as property.
The fact that your ex signed the Adoption papers means that legally the dog is his property in any event - the address issue is sadly not relevant.
In addition you gave up any further claim you might have had when you asked his parents to have the dog and they eventually accepted.
I am sorry - I appreciate that this is devastating for you but sadly I have no better news that I can give you
Please ask if you need further details