I live in Delaware and I was wondering if the law considers miniature horses as livestock/farm animals or pets? Also how much room is required? I've heard some people say law counts them as one horse and other people say they count them as 1/2 a horse!?
I'm not even in the same country as you so my thoughts in the matter may not be relevant, BUT...
I was almost given a Mini colt for my 9th birthday [he would have been gelded ASAP had we been able to keep him]. It was intended that he would live in our HUGE backyard in a residential area, because it was just the perfect sized yard for a Mini and there was no way in heck he was escaping from THAT fencing [6 foot high, totally solid, not even the most talented escape artist had a hope of getting out of it!]. Neighbours were all cool with it and for the brief period we had him there, they all thought it was the best thing EVER to have a pony on the street. The problem was local law.
A horse, regardless of size, is a hoofed animal, and therefore considered livestock. Because of local law, and the zoning of the property [residential], it was illegal to keep livestock on the property concerned full stop.
Rural, special rural, or rural residential would all have been absolutely fine zonings to keep a Mini on [block size does make a big difference here, of course; some rural residential blocks aren't big enough], but not straight out residential.
It very much depends on your property, its zoning, and the laws in your area. One city council/shire council will have different laws from the next here in Aus, and I have definitely heard of counties in America having different laws from the next county over.