Identify this Eastern European short?

[George White]

A late 70s/early 80s Eastern European cartoon - very colourful, following a boy, tall, lanky, with a quiff of darkish hair, very psychedelic, bouncy, possibly involved the boy (and his tweedy, moustachioed, bespectacled father, possibly) chasing a dog, psychedelic backgrounds going on in the back. I once saw it on youtube, where it had been re-edited to accompany Popcorn by Hot Butter. But it's since been taken off.
I think I looked it up, and found the animator, who was someone quite prolific, but since long forgotten his name or nationality.
And it's not Nu Pogodi.
Either Hungarian or Yugoslavian or Czech.