“Suffering is suffering, and deprivation of happiness is deprivation of happiness, regardless of the being who is suffering or the source of the suffering. This is the main antispeciesist claim, and it can be applied not only when we consider the interests of humans versus those of nonhumans, but also when we consider the interests of different nonhuman animals.

Opposition to speciesism doesn’t only mean rejecting human disregard for other animals. Speciesism is the discrimination against those who don’t belong to a certain species. So we can be speciesist if we discriminate against some nonhuman animals to favor others, such as accepting worse treatment of pigs than dogs. Antispeciesism thus implies that we must reject the favoring of some nonhuman animals over others for unjustified reasons. This includes rejecting the favoring of domesticated animals over those living in the wild.”

— Animal Ethics, Wild Animal Suffering