Musannaf Ibn Abi Shayba 13:1887

Abu Bakr narrated to us, he said: Abd al-A’la narrated to us, from Ma’mar, from al-Zuhri, that he used to say: If a disease occurs in [the animal] that is other than the one for which it was concealed (tadlis), then it is valid according to him, and he deducts from it what that disease deducts from its price.