Source text
وَبِمَوْتِ كَلْبٍ أَوْ شَاةٍ أَوْ آدَمِيٍّ فِيهَا
• If a dog, sheep, or human dies in the small well, complete drainage is required under the rule stated here.
• A useful distinction from the commentary: if a dog falls in alive, comes out alive, and its mouth does not reach the water, the water is not made impure merely by the dog's body.