EC can be treated successfully with panacur (fenbendazole) or oxibendazole for 28 days. Fenbendazole is the preferred drug, but for buns that don’t do well on it, oxibendazole is another option.
Metacam (meloxicam) helps bring down the tissue inflammation that happens due to the ec.
For vertigo and vertigo-related nausea, some vets prescribe meclizine (an antihistamine).
Treatment doesn’t completely eradicate the ec parasite, so it’s not technically a cure. But it can make the condition manageable and many buns never relapse. It is definitely worth a shot. Panacur is inexpensive and well tolerated by most buns. It can take quite a while before you see improvement though. Meanwhile you should make sure her living area is made up so she cant hurt herself, and you might have to support feed and help her with her personal hygiene.
Thank you for the update! Fingers so very crossed for her!