Can be seen here.
Though fair warning there's the resolving of an ongoing plot line around that review. If you watch AT4W, ever.
Difference is I will reject any and all evidence to the contray. Shoot cannon at canon if need be.I think to be honest, that's a pretty widespread Fanon.
Personally I'm not fond of it though. It's almost like saying that it's not okay to be different (from other dragons) and/or that spike is somehow less of a dragon for lacking them.
I just happen to think dragons should fly, it more majestic and what not ties in better to the imagery of dragons as the most powerful beasts of lore. Sure its just acquired and not even historically true of western dragons... but ehh this isn't rational.
(And seriously every dragon but has them in show...)