A man asked Sayyiduna Ali (may Allah be pleased with him) about the sacrifice of a cow. He replied that one cow suffices for seven people. The man asked, "What if its horn is broken?" He replied, "There is no harm." He asked, "What if it is lame?" He replied, "If it can walk to the place of sacrifice by itself, then slaughter it." The Prophet (peace and blessings be upon him) has commanded us to "carefully examine the animal's eyes and ears."