"Descartes reasoned that since animals are not rational, they are not conscious, and since they are not conscious, they cannot even be aware of pain; their piteous howls during the horrible experiments he conducted on them were to him mere reflex, the unfelt expression of material reactions akin to the shrieking of a teakettle."

The Cartesian world view on biology has been catastrophic to our fellow mammals and even today aspects of this perspective survives. Physiologically, humans are not very different from other mammals, even if we want to be. We all have a limbic system and that means we all have the same emotions. Animals have feelings and emotions. When things happen to them, they react with emotions be it sorrow, anger, happiness, fear.