I've found a couple of different certification programs.
Equissage: Equine Massage and Canine Massage Certification
The Art of Equine Massage Therapy
Equine Massage Therapy by EquiTouch®
Darcy Lane School of Massage Therapy Equine Massge Therapy
How should I go about deciding on which program? They all seem good.
Also, if anyone does equine massage therapy and would like to share any advice, it would be greatly appreciated :)