I also must add that I, too, hoped that was a solution for my problem. I really, really, really wanted horses for a long time. I had hoped they wouldn't take up a valuable space in the household, but alas, they do, just as in Sims 3. I really hated that -- having to decide, horse or baby. But there wasn't anything set up for renting even so much as a stable. Most people I'm aware of didn't live on a ranch, but had a horse, so they stabled it elsewhere. It still required they go and see to the horses needs, but that would be okay with me.
We can only hope a modder will come up with something to fix this flaw.