The value of an animal is intrinsic and universal, in-so-much as it is the value of life. While it is hopelessly romantic to profess an unyielding devotion to the health and happiness of a pet, the practice highlights the disparity between the application of value to one creature over another. Actual monetary value in this case is subjective and irrelevant. The application of that value, however, demonstrates the selfish nature of humanity.
We choose to value the people and things in our lives, to value one species over another, to value individuals we share identity with over those we do not; everyone does this. We place a value on people and things for a multitude of reasons, but that value is never applied universally. I would pay for an expensive surgery for my dog, but probably not my good friend's, and definitely not a stranger's. I would sell my car to help pay my father's medical bills. I might contribute a small sum to a charity aimed at stopping
honor killings. I will not give that pan-handler my change. I am the only commonality among these decisions. And I make all of these choices based on selfishness; a desire to feel good about myself.
The true (un)value of life is made resolute each and every day. The grotesqueries of factory farming and commercial fishing in food production, the destruction of natural environments that will forever change the life and climate systems of the entire planet, are both clear indicators of how much we value life. Claiming to be in opposition to such things would be to claim opposition to breathing. Each of us is invariably connected and thereby supportive of these systems.