"The Messenger of Allah commanded us to examine the eyes and ears (of animals), and no0t to sacrifice and animals with its ears slit from the front, and animal with its ears slit form the back, a animal with its tail cut, nor an animals with a round hole in its ear."  

أَمَرَنَا رَسُولُ اللَّهِ ﷺ أَنْ نَسْتَشْرِفَ الْعَيْنَ وَالأُذُنَ وَأَنْ لاَ نُضَحِّيَ بِمُقَابَلَةٍ وَلاَ مُدَابَرَةٍ وَلاَ بَتْرَاءَ وَلاَ خَرْقَاءَ