Legal Question in Civil Litigation in California

Goo to the police and file a report. The dog is legally yours and you never authorized anyone to give it away.

How awful. The dog still belongs to you. The 5-day rule invoked by the person who now has the dog does not exist.

If your acquaintance is the one who gave the dog away (and assuming he had no reason to think you'd authorized him to do so) then he is almost certainly guilty of a crime. He should also be liable for damages, though the extent of that liability will depend on what happens.

Whether the person who now has your dog is also guilty of a crime is less clear. If he did not know the person who gave it to him wasn't its legal owner, then he probably hasn't committed a crime. That wouldn't mean he can keep the dog; as I said earlier, the dog is still legally yours. But it may mean you will have to sue him in order to get the dog back. You will probably need to name both him and the acquaintance who gave your dog away as defendants.

Once your lawsuit has been filed and the defendant has been served, you can ask the judge to order the dog returned to you promptly so that you won't have to wait until the entire process has run its course. You should have a lawyer help you with this -- and preferably with the entire lawsuit -- to make sure it's done correctly. The acquaintance who gave your dog away should be responsible for paying your legal bills, but my guess is he doesn't have that kind of money.

Good luck.