Is it only humans who can understand Buddhism?

If Buddhism is a general theory of understanding the cycle of attachments, is it possible that any other 'wise' enough creature could achieve the same thing? In the Visuddhimagga English translation, a creature who can understand this theory is called 'a wise man'. In the Visuddhimagga Sinhalese version, a creature who can understand this theory is called as a creature with 'Trihethuka Pratisandi'. i.e. Tri (three) + hethuka (caused by factors) + Pratisandi (birth): 'A birth caused by three factors' (Pali: tihetukapa.tisandhi).