Being Sued For My Cat. Can I Fight This?

LOCATION: Texas

Any help would be appreciated, my main question with all of this is, do I have a good case against this because of the context, do I need to get an attorney, or do I have no case because of what my cat's microchip says.

I've just received notice I'm being sued in my local small claims court by my ex-girlfriend for the rights to my cat. My cat is my family, and I want to do everything in my power to keep them. If I have to pay a lawyer, so be it.

My ex is not from the U.S. and is still not a citizen or living here as far as I'm aware, and hasn't listed she has an attorney. Some context for her, I caught her cheating on me before we got married, while I was preparing documents for a Visa application for us.

To give you some background about the cat. My ex originally got the cat in her home country, but was told by her parents (who she was living with) that she needs to keep the cat outside, then eventually completely get rid of the cat because they didn't want it there anymore.
She asked if I could take him in America, and I agreed. In total, she had the cat with her for maybe a few months. Then she came to America to bring him, we took care of him together for 2 months, then she left and I was left as the main caretaker for him. I proceeded to care for him for another several months. She then came back to the U.S. for a vacation, which is when I caught her cheating, and we broke up and she went back home.

When she left, she asked if I could take him or if she needed to figure something out, and I said I'll keep him. Then, about 1 month later, out of the blue she says she wants the cat back. I said no, because she said I could keep him, and suggested I go to the vet to try and change the microchip. I've been caring for him for about a year at this point. We argued, and she stopped responding.

Cut to now, it's been 2 full years since that argument, no response or financial help for the cat, and I get notice saying she's suing.
So ultimately I just want to know, if her name is technically on the microchip, do I have any chance to keep my cat? I wanted to argue that I have been loving and caring for this cat for 85% of his entire life at this point, and someone wants to take them away to a different country, where he was going to be given away initially anyways. But I don't know if that matters given animals are considered property.

I have evidence of my ex being mean and hateful to me before we broke up, and evidence of myself taking my cat to vet visits, getting medicine, etc... so would it be a possibility the judge acknowledges this?