I don't know. But I don't think too many other omnivores were usually eaten: cows, chickens, sheep, even horses are all herbivores. To a larger point, the impr

I don't know. But I don't think too many other omnivores were usually eaten: cows, chickens, sheep, even horses are all herbivores. To a larger point, the imprecision of the rule would have been dictated both by customs and limitations in knowledge of the time: culture inasmuch as there would be no need to restrict eating omnivores that nobody ate anyway, and knowledge would dictate how precise you could be while still being safe: we now know that pork is ok to eat, but only because we have the tools to reliably determine whether pork is tainted, and build processes and supply chains that minimize that. For civilizations that didn't yet have that insight, much safer to avoid the whole thing.