Musannaf Ibn Abi Shayba 13:2598

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Sufyan, from Ghaylan, from al-Hakam, regarding a man who bought a beast and caused it to become thin, then found a defect in it. He said: He returns it, and returns with it [the value of] the difference between the thinness and the fatness.