cbe99d57_Common_Degu_Illnesses__0
[1] Part of tail missing, tail appears shorter than normal or stump-like. Tail hanging off or broken. [2] (Also see here) [3] Various, degus shed their tail as an anti-predatory mechanism when restrained by the tail. Could also be caused by trapping the tail in something, such as a wheel. [4] Remove all hazards from environment. Do not hold degu by the tail (except near the base of the tail). Avoid using wheels with spokes in the cage. A degu will bite off the remaining part of the tail itself. The tail will never re-grow. [5] GOOD [0] 
Tail
Common Degu Illnesses
0