I give my pony Vit E orally every evening. Put dose (say 3-5 ml) in a needle-less syringe. Grab a cookie. Give pony cookie- squirt syringe in corner of mouth onto tongue while he is eating cookie.
After a few weeks he started opening his mouth wide when he sees me coming with the syringe. (It’s very cute, actually.) Squirt Vit E then give cookie. Happy pony.