Horses, donkeys, mules and llamas spawned from spawn eggs or /summon command have 53 health

The Bug

AbstractHorse entities can have up to 53 health points.

Expected Behavior

Any AbstractHorse creature should have a maximum of 25 health points.

How to reproduce

1. Use a spawn egg to spawn a horse
2. Inspect the horse's health:

   /data get entity @e[type=horse,limit=1,sort=nearest] Health

   → The horse has 53 health

Code Analysis

The questionable value can be found in the AbstractHorse class:

public static AttributeSupplier.Builder createBaseHorseAttributes() {
    return Mob.createMobAttributes().add(Attributes.JUMP_STRENGTH).add(Attributes.MAX_HEALTH, 53.0D).add(Attributes.MOVEMENT_SPEED, 0.22499999403953552D);
}