Does keeping a guard dog in an apartment prevent the angels from entering, or is it an exception for the purpose of guarding?

The jurists' opinions differ regarding whether a dog permitted for keeping, such as a guard dog, prevents angels from entering a home. An-Nawawi holds that it does prevent their entry, while Al-Khattabi and the Permanent Committee for Scholarly Research and Ifta' are of the view that the prohibition is specific to dogs that are not permitted to be kept. As for a dog that is permitted to be kept, it does not prevent angels from entering. Previous fatwas have been issued clarifying these opinions.