Bet it isnt a horse trailer. Horse trailers have standards stock trailers don't. Not saying lots of stock trailers arnt great, safe trailers. But I have seen some that have under rated axels, and other cheap short cuts that would make them unsafe for horses. Of course the manufacturers are very careful to avoid the use of the word "horse" in any literature.
This is a 2006 one horse trailer how recent are these laws and are they from state to state? Also is it dependant on the weight to be trailered? Or is it all stock trailer not technically 'horse' trailer