I remember seeing a book in my elementary (or possibly middle school) library that I would like to locate again. It was something that I wanted to read, but then I think the book disappeared, so I never got to. The physical book did not look new when I saw it in the 1980s, but my elementary school was only built in the 1970s, so there is a good change it was published between 1970 and 1985.
I think the blurb on the back was what interested me, or maybe I read the first few pages. I think the main character was an human teen, who had grown up as an alien on a planet mostly inhabited by uplifted animals. Now, the planet was about to be invaded by "aliens" (actually other humans), and he would find himself torn between the invaders and his animal friends.
The paperback cover, as I recall, had a white background, with some dark and unrealistically colored images of a person against a background that I couldn't recall. I think it had a kind of overall psychedelic look—which again probably points to a 1970s publication date.