He does look wierd, like his butt is 4" too far back haha! He is fairly thin and lacking muscles across his topline and stomach which could emphasize it, but there is deffo summet off with his conformation O.o He looks butt high, but his withers and croup are pretty even when you put a ruler against them, but he could still be young and when he's grown up he might no look so oddly shaped...?
Well besides being a bit butt high.. also seems to have a "herring gut" I think
I believe sky is correct. I find it mostly in thoroughbreds. Do you know what breed this horse is? Also looks to me like they could use some groceries! You shouldn't be able to see the ribs but just enough covering over them that you can feel them without have to press to hard.
The horse is hardly lacking muscles. Probably in "racing form" of fitness, which means not an ounce of fat, and a lot of muscle, especially on the hind. The confor is "wasp wasted" or as Sky said "herring gutted" .
This is a Quarterhorse (I believe appendix QH) in "racing condition" so he appears wasp waisted. His croup is steep and he is butt high. His coupling appears weak and long, but that is often how a racing condition horse looks.
He has a nice shoulder that yells "Thoroughbred" and that is what tells me Appendix QH.
I think if he were let down you would find him a pretty good looking animal.