Horses on the Planet of the Apes? Not Cool Man, Not Cool

Not much is expected to make a whole lotta sense in a world where Charleton Heston is supposed to be representative of the human race... still, a form of, what I'll generously call logic, feels like it dictates the ape society. They have a functioning, albeit slightly skewed, set of laws, indicating that there's a clear set of actions and consequences. However, Charleton Heston is persecuted for... I don't know what the legal term for it is, but basically being a douche and not hairy. Fast forward to the end of the movie when Charleton heston is escaping and he's runnin' on the beach or whatever, with the humanoid apes in tow. How do they catch up to him so fast? They ride horses... I'm sorry, but does nobody else find this weird that the apes in Planet of the Apes ride horses? I mean, don't get me wrong, I go to film school so I understand "suspension of disbelief" which is a pretty crucial concept in watching a movie where apes rule the world, but still, I mean, apes are heavy motherfuckers. I'm no equestrian, but I don't think horses can even carry that much weight directly on their backs... The weight issue aside, it just seems kinda douche-y that apes are making horses their bitches. I mean, apes have been oppressed before so they should understand where the horse is coming from. A little solidarity between apes and their horse brethren doesn't seem like it's too much to ask, but evidently the apes just aren't havin' it. Whatever, apes are douche bags.
PS I'm aware this is less than eloquent...
PPS Charleton Heston is also a douche