Is dog hair or cat hair considered najis? And will prayer not be valid if there is dog hair on you?
Dog hair is impure (najis). The cut hair is not najis but it should not be on your body, clothes, or the prayer place during the prayer. Cat hair is not najis, if there is one, two or three cat hairs on a person’s body or clothes their prayer is in order but if there are more than that, the prayer becomes void, as an obligatory precaution.