Q. After slaughtering my Qurbani sheep, I found an abscess on the lung of the sheep. Is my Qurbani valid?
A. If at the time of slaughter, your Qurbani animal was free from all visible and major physical defects (your Qurbani animal was not blind, sick or limping etc.), then the slaughter of such a Qurbani animal is valid.
An abscess found on the lung of a sheep after slaughter does not affect the validity of your Qurbani as it is insignificant and was not visible at the time of slaughter.
Thus, in the enquired case, the Qurbani of your sheep is considered valid. (Shaami 6/323)
Allah Ta’ala Knows Best
Mufti Ismaeel Bassa