[かませる, kamaseru] (v1) (1) (uk) to force something into someone's mouth (i.e. a gag); (2) to wedge something into a space, filling it; (3) to feed someone (something)
[ふくませる, fukumaseru] (v1, vt) (See 含む) to soak; to saturate; to suckle; to make one hold something in the mouth; to include; to instruct; to make one understand
[うまをみずべにみちびくことはできるがうまにみずをのませることはできない, umawomizubenimichibikukotohadekirugaumanimizuwonomaserukotohadekinai] (exp) (id) You may take a horse to the water, but you cannot make him drink