This excerpt is taken from Sheikh Farooq Rafi Sahib's book Qurbani, Aqiqah, and Ashra Zil-Hijjah.
If an animal's tooth is broken or injured, it is not a defect that prevents it from being sacrificed; rather, the sacrifice of such an animal is permissible.
Ubaid bin Firoz, may Allah have mercy on him, narrates that I said to Sayyiduna Bara bin Azib, may Allah be pleased with him:
فإني أكره أن يكون فى السن نقص، قال: ما كرهت فدعه، ولا تحرمه على أحد
"I consider a defect in the tooth of the sacrificial animal to be disliked." Sayyiduna Bara bin Azib, may Allah be pleased with him, said: "Leave those animals that you dislike (i.e., do not sacrifice them), but do not declare them forbidden for others."
Reference: Authentic: Sunan Abi Dawood: 2802
Therefore, defects in animals that are not prohibited by Shariah do not prevent sacrifice, and only those defects prevent sacrifice which are established by the Pure Shariah. Hence, one should avoid self-made interpretations, explanations, and intellectual sophistries regarding the defects of sacrifice because no Shariah ruling is established based on personal likes or dislikes.
The tail of the sacrificial animal being cut or injured is not a legal defect, and the sacrifice of such an animal is not invalid. Moreover, the narration that prohibits the sacrifice of an animal with a cut tail is weak. Sayyiduna Ali (may Allah be pleased with him) states:
أمرنا رسول الله صلى الله عليه وسلم أن نستشرف العين والأذن ولا نضحي بمقابلة ولا مدابرة ولا بتراء ولا خرقاء
"The Messenger of Allah (peace be upon him) commanded us to carefully examine the eyes and ears of the sacrificial animal, and not to sacrifice an animal whose ear is cut and hanging from the front, or whose ear is cut and hanging from the back, or whose tail is cut, or whose ear has a round hole."
Reference: Weak: Sunan an-Nasa'i, Kitab al-Dahaya, al-Muqabala wa hiya ma qata'a taraf udniha: 4377
"Zakariya ibn Abi Zaida is a tadlis (a narrator who conceals defects), and Zakariya ibn Abi Zaida's narration from Abu Ishaq Sabi'i is established after mixing, due to these two reasons this narration is weak and also rejected because it contradicts trustworthy narrators, since the other narrators use the word بتراء (prohibition of sacrifice of an animal with a cut tail) instead of sharqa' (an animal whose ear is cut lengthwise or widthwise)."
Also, another narration that tries to prove the tail of the sacrificial animal being cut as a defect is also weak.
It is narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him):
اشتريت أضحية فجاء الذئب فأكل من ذنبها، أو أكل ذنبها فسألت رسول الله صلى الله عليه وسلم فقال: ضح بها
"I bought a sacrificial animal (a sheep) and a wolf came and ate its tail, so I asked the Messenger of Allah (peace be upon him) about its sacrifice, and he said: 'Slaughter this very animal.'"
Reference: Very weak: Musnad Ahmad: 78/3-11760. Jabir ibn Yazid ibn Harith al-Juhani is abandoned (extremely weak) narrator and Muhammad ibn Qurtah ibn Ka'b al-Ansari is an unknown narrator, and also its transmission from Abu Sa'id Khudri (may Allah be pleased with him) is not established.
