Hamster wet tail disease is not a disease directly associated with the animal’s tail. One of the symptoms of the disease is diarrhea, and it is discharges of fluids from the anus which cause the tail to be wet. The wet tail is therefore a symptom of a disease possibly caused by a bacterial infection.Keep Your Fingers Crossed – Hamster wet tail disease is one of the most common, if not the most common disease hamsters are susceptible to. As is the case with a number of other diseases a hamster can be subjected to, wet tail is often fatal. It is treatable, but as is the case with hamsters, and many other so-called pocket pets, their small size can make treatment difficult and often when symptoms are first noticed, it is already too late. It can be a little disheartening to learn that a common disease of hamsters quite often does not have a positive outcome.