Who Decides/ Right And Wrong

Ok guys this is something that's bothering me and really got me to thinking who does decide, what is Animal Abuse? I have my own opinion on what I think the definition of that  is and a lot of that would be really obvious stuff but that's not really what I want to talk about. I want to talk about the more subtle aspects of the topic. I want to talk specifically about horses. I  want to start out by saying that for the most part and in my small circle I don't see a lot of what I would call Animal abuse but like I said.... small circle ( I'm sure it's out there) Anyhow it was my misfortune the other day to see things that really bothered me, I saw a bunch of horses that pretty much look like S### but the really sad thing was seeing a pathetic foal that I believe is a weanling standing in the mud on three legs( Ok this is where I may start to get off the beaten path but bare with me)this foal looks like a miniature pony baby( for all I know it is) the mother is a regular horse size, anyhow this foal is bones with hair and the mother is not much better. I could see only part of the injury to the front of the foals fetlock area, it looks to be a large deep gash, I'm guessing from being caught in something. There is also another horse in with these two and it goes after the foal.....that can't run away from it so he hobbles painfully away as fast as he can.....it looks horrendous.......So this brings me to my point. All these horses look like they need deworming, they all have food( although it doesn't look that good) and lots of it. They are standing in crap and the endless mud day in and day out.The area that the foal is in is small.....and I mean small......mud and on a hill. There is free feed hay in the pen but they look like they are starving so I'm getting there........my point is who decides what is right or wrong....now this is a no brainer for me........Wrong .....Wrong.......Wrong and oh so Wrong.....but even though I feel this way other people may not. After all there is food all over the place, they are not living in falling down fences with wire all over the place, it's not like their feet are rotting off or anything......but is this kind of care Ok or is it a form of animal abuse.  I think I have some pretty high standards when it comes to my responsibilty for the care of all my animals but I'll bet people could come in here and knock me too....I have some  fences in dire need of repair are they dangerous ....maybe but I keep my horses out of those areas. My poop isn't always cleaned from the pens right away is that unhealthy....maybe. I haven't had any sick horses or cuts and scrapes that don't heal properly. I feed my horses what I think is good horse hay but I'm not an expert...... so what do I know.... I could be feeding crappy hay.  Our horses are on a regular deworming program and they are somewhat chubby and sassy, they show a zest for life....but just because they don't have the obvious symptoms of worm infestation doesn't mean they don't have any. I guess I'm trying to figure out if I'm just being a judgemental B#### and should mind my own business or ? What do you think .....what are your parameters for animal abuse.... what is acceptable....... and really... who decides?