It was narrated from Kabshah bint Ka'b, who was married to one of the sons of Ab Qatadah, that: She poured water for Abu Qatadah to perform ablution. A cat came and drank the water, and he tilted the vessel for it. She started looking at it (in surprise) and he said: O daughter of my brother, do you find it strange? The Messenger of Allah said: 'They (cats) are not impure, they are of those who go around among you.'
It was narrated that 'Aishah said: The Messenger of Allah and I used to perform ablution from a single vessel, when the cat had drunk from it beforehand.
It was narrated from Abu Hurairah that: The Messenger of Allah said: Cats do not invalidate the prayer, because they are one of the things that are useful in the house.