Assumably the use of herbs and trees in cases of wounds and ailments was, as has been observed in several other cultures, partly based on the observation of animals. This is mentioned by several classic European authors (such as Plinius and Aristoteles) and cited and confirmed by medieval authors such as Brunfels. The study of this kind of phenomena has long been neglected but it has recently gained new interest and a new name: Zoofarmacognosy
This is an interesting clip borrowed from the "Peculiar Potions" episode of BBC's series "Weird Nature" - A Jaguar in the Peruvian rain forest eats Yage (banisteriopsis caapi), a vine containing hallucinogenic chemical harmaline and other beta carbolines, used by natives in a ritualistic ceremony involving Ayahuasca. (it's the one of the two ingredients, the other contains usually DMT).