There are two main views on dogs in Islam. One view, and the most common one is the Shafi'i madhab, which considers dogs to be najis (ritually unclean) while the Maliki madhab differs, and considers dogs to be pure.1
So with that, we understand that if you are of the Maliki madhab it is viewed as halal to own a dog.3 (Keeping it in your home if a different story.) The Shafi'i madhab on the other hand, prohibits ownership of dogs, except for hunting, herding, farming, and or guarding.
As for keeping your dog in your own home, for Shafi'i madhab adherents, it is viewed as strictly haram (understood on a textual basis), while for Maliki madhab adherents view it is makrooh only.2 Maliki madhab adherents draw this conclusion from hadith reference 4, they see it as a show of indication that it is not haram, just makrooh.
1:Ahmad Ibn Muhammad al-Dardir, al-Sharh al-Saghir ‘ala Aqrab al-Masalik
2:Whoever would keep a dog for other than hunting, herding or farming will lose a great reward every day. - Bukhari
3:Dalil Falihin ala Riyad al-Salihin; Hashiya `Adawi ala Sharh Kifaya al-Talib al-Rabbani
4:The angels (of blessings) do not enter homes with statues, drawn pictures of live beings or dogs. - Bukhari/Abu Dawood