"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."
Sunan an-Nasa'i Book 43, Hadith 12
← Previous Hadith "I heard the Messenger of Allah say" - and he gestured with his fingers, but his fingers were shorter than the fingers of the Messenger of Allah - he said "It is not permissible to offer as a sacrifice an animal that clearly has one bad eye, a lame animal that is obviously lame, as sick animal that is obviously sick, or an animals that is so emaciated that it is as if there is no marrow in its bones."

Sunan an-Nasa'i Book 43, Hadith 11 Next Hadith → "The Messenger of Allah commanded us to examine the eyes and ears (of animals) and not to Sacrifice and animal with a bad eye, nor an animal with its ears slit from the front, nor an animals with its ears slit form the back, nor an animal with a round hole in its ear.

Sunan an-Nasa'i Book 43, Hadith 13