Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 48
Sanskrit:
अथ गावश्च गोपाश्च निदाघातपपीडिता: ।दुष्टं जलं पपुस्तस्यास्तृष्णार्ता विषदूषितम् ॥ ४८ ॥
ITRANS:
atha gāvaś ca gopāś canidāghātapa-pīḍitāḥduṣṭaṁ jalaṁ papus tasyāstṛṣṇārtā viṣa-dūṣitam
Translation:
At that time the cows and cowherd boys were feeling acute distress from the glaring summer sun. Afflicted by thirst, they drank the water of the Yamunā River. But it had been contaminated with poison.