I've been searching for this movie for YEARS. Here's what I remember: a boy leaves his mother who gives him rice balls to eat, they were something that was shown because I know that he knew his journey was long and he had to save them.
There is a white dragon that gets hurt whom he befriends (I think?). The boy fights another dragon (red?). The white dragon was drawn like a traditional chinese dragon similar to Hoku in SPIRITED AWAY. It was definitely anime-style and had to have been made in the late 70's early-mid 80s. It was not made AFTER 1990.
I saw it in German BUT it HAD to have been in English...
What it is not:
- Dragon Ball (unless there's something before DB season 1 episode 1)
- Flight of the Dragons
- The Hobbit
- Neverending Story
- Nezha fights dragon king
- Last Unicorn
- Railway Dragon
- Merlin and the War of Dragons

I hope someone can help me!

It is also definitely not one of the Dungeon & Dragons..

Reminds me of the cut-scenes from Lunar: Silver Star Story.

Here's a list of some dragon anime. Don't know if you've already seen it in your searches. But if I come across the one you're talking about I'll be sure to post back for you.
Browse Dragons Anime | Anime-Planet


Here's another list:
http://myanimelist.net/anime.php?q=dragon

I am looking for it too.. I think it may be Taro the Dragon Boy.. I'm going to get it from Amazon and I will let u know. The synopsis doesn't say anything about rice balls but I remember the boys face and his mother being a dragon. Or something like that? Its been sooo long.. I just remember loving it when I was a child :)