If you use /summon EntityHorse ~0 ~1 ~0 {Attributes:[{Name:generic.maxHealth,Base:9999999999],Type:0,Tame:1,SaddleItem:{id:329}} then the horse healths will not show, they only show the first 30 hearts.
MC-92471
Horses health don't display
Resolved
Works As Intended
0
I believe that horses aren't meant to display more than 30 hearts. if you think about it, that command would make the horse display
49,999 1/2 hearts on-screen, which would be ridiculous and impractical. since the most a survival horse can have for health is 30 hearts, I'm guessing they capped it there for a reason.