Looney Tunes and Time and Jerry didn't wear clothes, or pretend they were people.

The Looney tunes characters were all animals in animal settings, personified for comedic effect.

Then you've got all that Don Bluth stuff that is definitely furry, which kicked of a lot of furry imaginations.

Also pretty sure Disney is responsible for a lot of furries. Gadget alone fucked up a lot of kids.