Does swelling in the throat of a ram prevent it from being sacrificed for Eid al-Adha?

For a sacrifice (udhiyah (definition)) to be valid, it must be free from apparent defects, based on the saying of the Messenger of Allah, peace and blessings be upon him: "Four are not permissible in sacrifices: the one-eyed animal whose defect is obvious, the sick animal whose sickness is obvious, the lame animal whose lameness is obvious, and the emaciated animal that has no marrow." So, if the tumor in the ram's throat is an obvious illness, then it is not permissible. Otherwise, the sacrifice is valid, though an animal free from all defects is preferable.