Many animals experience pain, anxiety and suffering, physically and psychologically, when they are held in captivity or subjected to starvation, social isolation, physical restraint, or painful situations from which they cannot escape. Even if it is not the same experience of pain, anxiety, or suffering undergone by humans- or even other animals, including members of the same species- an individual's pain, suffering, and anxiety matter.
Marc Bekoff (2007). “Animals Matter: A Biologist Explains Why We Should Treat Animals with Compassion and Respect”, p.67, Shambhala Publications