Uniko/Unico - is a unicorn who helps people who show love towards him, but he is cursed to forget them after he's become friends with them. He was created by Osamu Tezuka. There are three movies about him:
-Kuroi Kumo Shiroi Hane (1979, Japan)
-Unico (also known as Fantastic Adventures of Unico) (1981, Japan)
-Maho no Shima (1983, Japan)
The Last Unicorn (1982, USA) - Rankin Bass adaption of the novel by Peter S. Beagle. All hail our overlord Amalthea! Seriously, which MLP fan doesn't like Last Unicorn at least a bit?
Ico, el caballito valiente (1983, Argentina) - Ico and Preciosa look eerily similar to FiM ponies, just with better anatomy. I fully believe Lauren Faust ripped their heads off and planted them onto G3.5 bodies
I see a pattern... the early 80s loved these magic horsies. Of course there is also talking horse sidekicks like the She-Ra and Rainbow Brite horses Swiftwind and Starlite.
Can you add more to my list?