I believe that most arguments for the immorality of animal experimentation take one of two forms: First, I believe that they should either follow Peter Singer’s leads or know that in some cases animal experiments is morally unforgivable on utilitarian grounds. Second, I believe they should insist that the animals being experimented on have the very same rights which deliberate rights on humans. As a result, experimenting on these animals is wrong because it violates their rights.
So, again, if we only cared about humans, we would have good reasons for not deciding on animal research, but in the end we don’t only care about humans. We think that animals should not be harmed or killed for no good reason.