I have read this and now I will weigh in....
According to all modern law, pets are chattel -- the same as cows and roosters.
Current law is starting to slowly catch up to the idea of pets as family members. At least you can get vet bills, even when they exceed the "street value" of the pet.
I think that negligence that leads to the death of a pet should be subject to pain and suffering for the pet's owner. That is pretty much the last barrier to a proper legal recognition of pets. Pets can love and are certainly loved. The death of a pet can cut deeply into all members of the family. That does not make them "sentient beings" as the primitive portrays.
They are "sentient,"but not as the primitive portrays. In the case of cats, they are superior beings, as any cat can tell you with a single expression.
My Neysa and Musica were intelligent creatures who loved me and Mrs. FD and received love in kind. That didn't give them any kind of "rights" -- but it made them special.