Islamic scholars state that if an animal, other than a dog or pig (or their offspring), falls into water less than the quantity of "Qultayn" and is rescued alive, the water will remain pure, provided the animal does not have any impurity on its body. However, if a dog, pig, or their offspring falls into the water, the water will become impure because these animals are considered inherently impure. (Al-Tahdhib: 163/1)