Is it permissible to own a dog for the purpose of playing and then guarding, and does it prevent angels from entering the house?

It is impermissible to buy dogs except for hunting or guarding. There is no objection to buying a dog for guarding if there is a need for it, provided it is not brought into the house, to avoid defiling utensils, furnishings, and clothes, and because angels refrain from entering a house in which there is a dog. As for buying a dog for playing, it is not permissible.