Animal rights theory, most famously articulated by philosopher Tom Regan, rejects the welfarist premise entirely. Regan argued that animals are what he called "subjects-of-a-life": beings with beliefs, desires, memory, a sense of the future, and an emotional life.

argue that it is philosophically impractical. If a rat has a right to life, do you call an exterminator for an infestation? If a deer has a right not to be killed, do you let it starve in an overpopulated forest? Furthermore, a pure rights view ignores the reality of predation in the wild: a lion violates a gazelle’s "right to life" daily. If rights are natural, should we intervene? (Most rights advocates say no—intervention in ecology is different from ending human domestication.)

The review highlights the complexities and challenges associated with animal welfare and rights. While significant progress has been made, there is still much work to be done to ensure the humane treatment and protection of animals. By continuing to raise awareness, advocate for policy changes, and promote a culture of compassion, we can work towards a future where animals are treated with the respect and dignity they deserve.