Intelligence and curiosity are primary descriptors for the domesticated goat (Capra aegagrus hircus), which has proven he's trainable as a working animal. It makes sense you'd assume you can house-train such a smart creature. But the fact is, a goat's not a suitable house pet, period.
"Housebreaking," or teaching a creature to urinate and defecate outside, is part of house-training, which goes beyond just waste elimination, covering indoor living in larger terms. The difficulty with house-training a goat is the goat's natural eating and eliminating habits. Goat constantly look for food and browse, eating as they go. They will then rest and ruminate before going back to browsing again. Amidst all this, they're pooping and peeing.
The fact is, you can teach a goat to urinate outside, but defecating is a different beast: Goats poop little pellets that goat farmers don't mind but homeowners mostly kind of do. Unless you're planning on providing constant food to your goat, sweeping up feces and not having friends and family over, keeping a goat inside is a bad idea.
Pitter Patter of Little Hooves
Goats have hooves. They're rough on flooring, and they're rough on furniture. Goats climb like -- well, like goats -- and they will perch on your countertops, your kitchen table and your couch. And there they will leave little pellets all over. Anything they can hop on is fair game, and anything on those items is likely to get knocked off, trampled, broken, eaten or pooped on.
Goats taste-test just about everything -- so your curtains, couch and new bedspread are on the menu. So are the potted plants, your computer cords and your stereo. They love paper, so bills, important documents and cash are first-devoured appetizers. It's unlikely you're going to break a goat of doing what comes naturally, so you will have to keep everything your goat can destroy away from him or keep him crated when you can't watch him.
Goats Love Company
If you're going to try to house-train one goat, you'll have to house-train at least two. Goats are herd animals that require the company of their own kind. A dog won't work as a goat friend; and, while your goat may love you, you're not a goat. Hence the need for a second goat. Keep them outside. You might be able to house-train one or a dozen ... but you really shouldn't. You'll be forever known in your hometown as that person who lives with goats. Even the cat lady will think you're strange.