H. J. McCloskey on Punishment of Cruelty to Animals

Animal Ethics

[T]here is another class of cases where the state is accorded the right to interfere with the individual when he is not interfering with any other person, namely, where cruelty to animals is involved. Legislation forbidding cruelty to animals represents the use of coercion against the interests of the individual coerced, and not to further the interests of any other person (it may do so but need not to be justified).