Suing ex bf for dog

Hello everyone my ex and I got a dog together however I paid for him, he’s registered to me, and despite the fact that he paid for most of the vet bills, the papers are under my name. We agree to share him but he ended up taking him and blocking me on everything. We both live in same state and county this all occurred btw. For those of you who have sued to get your pet back how did that process work and how did you go about getting them if you won the case?