Join Date: Oct 2009
Location: Just south of sanity
Lean doesn't mean skinny. Most TBs are lean. If his spine and hip bones are jutting out, then he's far too thin. You should be able to feel his ribs under the skin, but not see them.
If the horse is undernourished, then yes, he's going to be extremely calm. Many dishonest sellers under feed their horses on purpose to make them appear calmer than they really are. If they're starving, they simply just don't have the energy to act up.
I've seen horses do a complete 180 degree turnaround in temperament once they were getting the right amount of food and started getting their energy back.