Hello again Sue,
My name is Ben. I'm a licensed attorney (State Bar of Texas). Glad to try and help out.
Sure sorry for the circumstances, truly. My heart goes out to you. I say that in all sincerity, as I'm such a dog lover and can only image how grief stricken you must be at this time.
Accordingly, I'm pleased to say there are two things you can do, as follows.
First, you could file a professional complaint, free of charge:
Texas State Board of Veterinary Medical Examiners
Secondly, as you mentioned, you could seek legal counsel. To help folks in this online venue, I am required to follow site rules including refraining from accepting cases and/or making direct referrals to named attorneys. However, I can tell you where I would turn were I in your very shoes.
Here's a resource you can trust both in terms of economy and reliability:
Texas Lawyer Referral Information Service
If you have a follow-up question or need clarification, please just say the word by using "reply" to reach me.
I truly hope all works out for you.