Wet tail is one of the more common serious illnesses that can threaten your hamster. The disease gets its name from one its symptoms, persistent diarrhea, and it can be fatal if not promptly treated. The disease is more often seen in weaning-age hamsters, about 3 to 6 weeks old, but it can affect older hamsters as well. Any breed of hamster can develop signs of wet tail but teddy bear hamsters seem to be a little more susceptible than other breeds.
To learn more, read Wet Tail in Hamsters.