Sorry to hear about your loss, I too am a dog lover.

Off the cuff I would say, that 8 years ago when I was in law school I remember that in Texas the only compensation for the loss of a pet, is the replacement cost of the pet.

You could also ask for mental anguish, but it is an unlikely recovery, in that the standard in Texas is very high.

So CO offering you the price paid for your pet, I believe, is all that they would be liable except for may be other consequential damages, the refund of the pet fare, attorney's fees (if you sue them for breach of contract), and court cost.