People are thoroughly capable of believing this about other people, never mind non-human animals.
Where I live, if you were to palliatively medicate a dog or cat, or cow or pig or sheep, for ten years, in an effort to keep it alive despite obvious suffering, you would likely be servely reprimanded, if caught.
Meanwhile, humans have turned this treatment toward each other in to an industry.
We shouldn’t be at all surprised that we factory farm animals for our culinary pleasures.