Ex Is Sueing Me For A Dog He Bought Me

My ex purchased a puppy as a gift for me. He signed the contract with the breeder. We went thru a lot of shit, he was horrible. Long story short, I left him, and now all of a sudden he wants the dog back that he gifted me. She has been in my possession for over a year. She has never spent time with him without me unless he was at my house while I was at work. Anytime he'd go home he wouldn't take her with him. If we got into fights, same thing, he wouldn't take her. He would occasionally threaten me with saying he would take her. I have the original contract that was signed when he got her for me. When I received the court papers, he including a contract from the breeder that was NOT the original contract. They also put the wrong date of sale and I have photos time stamped with proof that I had the dog prior to this "contract" being signed. The breeder we got the dog from HATES me, I worked for her and witnessed her abusing animals in her care and I spoke publicly about what I witnessed. So, I know her and my ex are in cahoots with this trying to get back at me. The dog is licensed in my name, spayed in my name, has her vaccines in my name, and a vet exam in my name. The only paperwork he has is the fake contract they made up in order to sue me. I've paid for ALL of her expenses with the exception of the original buying price, he paid for that cause she was a gift. So, what I'm curious to know, is what should I expect from this? I don't really have the money for a lawyer, but I will do anything I need to do to keep my dog. He doesn't even take care of the pets he has so the last thing I want to happen is for her to be in his care. Does anyone have any insight? Or any tips to help me win this case????? Thank you so much in advance