Abu Dawud Book 20, Hadith Number 3710.

Chapter : Drinking from mouth of waterskin.

Narated By Ibn ‘Abbas : The Apostle of Allah (may peace be upon him) forbade drinking from the mouth of a water-skin, and riding the animal which feeds on filth and eating the animal which is killed in confinement.

Abu Dawud said: Jallalah means an animal which eats filth and impurities.