Q: Do I have legal grounds to keep a dog I've cared for over 2 years under an initial temporary arrangement?

A: In Maryland, and perhaps also in Pennsylvania (I am not a lawyer in PA) pets are considered property. You can only obtain as good legal title to property as the person you got it from had. I. Your scenario, if the person who entrusted their dog’s care to you had full legal title, meaning no other person had a legal interest in the dog, then your argument for keeping the dog as your own depends on whether the prior owner legally abandoned the dog. Legal abandonment, if proven, can transfer ownership in the abandoned property to the person now in possession of the property.

If, however, the person who gave you the dog did not have unrestricted full legal title to the dog—if there is a breeder contract that states ownership is not transferred but remains with the breeder, and the person receiving the dog under the contract can only maintain possession of the dog as long as the dog is with them, and may not be transferred to others, then they contract may be enforced. In that scenario, the breeder may sue for recovery of the dog. Of course they would need to sue you in Maryland, and would need to produce the contract. You might contest the action, depending of the terms of the contract, or perhaps other grounds supported by other facts you have not shared. You might reach out to the breeder and work out a deal to keep the dog to settle the matter. The breeder can sign a new agreement transferring the prior owner’s contract rights to you, or negotiate new terms. Or you can simply try and keep the dog and deal with any lawsuits if and when they come.