Sacred and unclean animals

[Chad32]

I agree that animals being considered clean was likely due to the ruling class liking those animals for whatever reason, and considering something unclean is likely because of illness due to poorly cooking the meat, or because the animal behaved in a manner that Humans would consider bad, or whatever. A common way for animals to keep bugs off of them is rolling around in the dirt, or staying cool by dipping themselves in mud, but all the Humans could see was the animal being very dirty and unappealing.