Most residential properties on 5 acre lots allow for horses to be kept and most of the lots in rural Spirit lake or Athol are on 5+ acres. What is the address of the home you're inquiring about?
The first issue on any rural property is "What is the zoning regulation?" secondly "Are there any HOA or CC&R restrictions which would supercede the county law?" The last thing to look for is what is being practiced by the neighbors currently ie: if the law says "yes" and no neighbors have horses, then you'll need to dig deeper. If several neighbors currently keep horses that is a good sign and yet you would be wise to check county ordinances and HOA restrictions.
I hope that is helpful to you.... more
With USDA and VA loans you really need to pick out a home that qualifies for the program. Sounds like you are out on acreage if you have a private well. These programs are really more suitable for homes in town on a smaller lot. As to well you can go to the department of water resources site for State of Idaho and look up the well log that should have been recorded with them when the well was drilled. They need to insure the water well is to specifications and has sufficient volume to close your loan. This should have been reviewed when you did your home inspections in a normal transaction. The well log will be under the owners name or by legal description. Good luck with your transaction.