1. If the animal is missing even one testicle, it is considered blemished.
2. An extra leg or a missing leg is considered a blemish.
3. Ila and Chachamim: A broken leg (front or back) is considered a blemish.
4. Two ears on one side of the head may or may not be a blemish.
5. If one eye or ear is clearly much larger than the other, it is a blemish.
A BIT MORE
1. The Mishnah discusses the process for determining whether a testicle is missing in cases where it is unclear.
2. Rav Huna: If the extra leg or missing leg is in the back part of the animal, it is also a Tereifah.
3. Rav Papa: Although a blemish normally must be recognizable, since a broken leg is obvious when the animal works it is considered a recognizable blemish.
4. The Mishnah states that if there is only one earlobe for both ears (i.e. one ear is on top and one on bottom, and the earlobes join), it is a blemish. If each ear has its own earlobe, it is not a blemish.
5. Rebbi Yehudah: If one testicle is twice as large as the other, it is a blemish. Chachamim: It is not a blemish, and it does not matter how much larger one is than the other (even if the small one is the size of a bean).