Is it in the Quran or Hadith that it is prohibited to keep dogs as pets at home? If so, please give the reference.

The scholars are agreed that it is not permitted to keep a dog unless it is for a purpose like hunting, guarding property or other uses that are permissible in Shari’ah. The Prophet (peace and blessing of Allah be upon him) said: "Whoever keeps a dog, except a dog for herding, hunting or farming, his reward will decrease by one qiraat [a very large measure] every day." [Reported by Muslim, 2948]