“I asked my X-girlfriend to watch my dog for a few weeks and now she has refused to give him back, are there any laws pertaining to a situation like this? Perhaps animal theft or kidnapping of a animal?”
Under most state laws, pets are considered personal property. It may not technically be considered “theft” (depending on your state law it might be called a form of “embezzlement”, “fraudulent appropriation,” or “unlawful conversion”). In any event, it is a crime and you should go down to your local police station and report it. They can take your statement and may be able to help you retrieve your dog quickly. You may be required to show some proof of ownership (records from your vet, licensing fee receipts, etc.). Depending on the value of the dog, such a theft could even rise to the level of a felony, so this could turn very serious very quickly.