Article: Dwarf hamsters can get severe diarrhea, but they do not get wet tail. Long-haired teddy hamsters, on the other hand, seem to be the most prone to wet tail. Ask your breeder or veterinarian about your breed’s risk of wet tail when purchasing hamsters, so you know your pet’s risks. Very young hamsters between 3 - 8 weeks of age seem especially vulnerable to an infection. This is likely because their immune systems are still developing, and aren't very good at fighting off bugs yet. Research suggests that most the bacteria most likely to case wet tail is the Desulfovibrio species. The most easily affected hamsters seem to be weaned baby hamsters up to the age of 8 weeks. Always give new hamsters time to adjust to their new surroundings before handling them too much. Otherwise, you might stress them out too much and contribute to wet tail conditions.  Give new hamsters about a week to settle in before handling them often. It is also a good idea to isolate them during this time, as wet tail can be incubating for 7 days before the symptoms appear. Adult hamsters tend to develop the symptoms if the balance of microorganisms in their guts is disturbed. This lets a bacterium called clostridium overwhelm the gut, causing diarrhea and wet tail symptoms. Factors which can trigger the initial gastrointestinal disturbance include:  Stress (for example, from an overcrowded cage or from fear of a predator like a house cat) Change of diet Certain antibiotics given by mouth for other illnesses It may well be that the gastrointestinal problems arise not from disturbances like stress or diet, but from an underlying medical condition. Conditions like irritable bowel syndrome or bowel cancer can be contributing factors to wet tail.

What is a summary?
Consider the hamster’s breed. Keep an eye on young hamsters. Don’t over-handle newly weaned hamsters. Be aware of gastrointestinal disturbances. Take the hamster’s other conditions into consideration.