Then again, medieval drawings of real animals weren't much better. And what they wrote about them was often just as inaccurate.
Then there's the running trope of "dog-headed men" being mentioned by various old school sources, including Herodotus. It's kind of a joke among historians, apparently. I could easily see it influencing the art design of Gnolls and Kobolds in AD&D, though this wasn't their intended Gygaxian design.