Just as we reject racism sexism ageism and heterosexism we reject speciesism. The species of a sentient being is no more reason to deny the protection of this basic right than race sex age or sexual orientation is a reason to deny membership in the human moral community to other humans.
I had the good fortune to be able to right an injustice that I thought was being heaped on young people by lowering the voting age where you had young people that were old enough to die in Vietnam but not old enough to vote for their members of Congress that sent them there.
A diplomat is a man who always remembers a woman's birthday but never remembers her age.