Ubaydullah bin Abdullah bin Umar narrates from his father (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) was asked about (the) water that is in open desert land which beasts of prey and dogs come to, and he (peace and blessings be upon him) said: "When the water amounts to two qullahs (large jars), it does not carry impurity (that is, it does not become impure)."
(b) Likewise, in another narration it says: "dogs and beasts of prey," and this narration is gharib (unusual).
(c) Muhammad bin Ishaq says: dogs and animals. There is disagreement concerning Ibn Ayyash in its chain.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1242