Diarrhea caused by Escherichia coli bacteria is a very common occurrence in hamsters, especially young and newborn hamsters with poorly developed immune systems. Typically, E. coli infection (or Colibacillosis) occurs due to unhygienic living conditions and is transmitted by ingestion of contaminated food and water, though it may also be transmitted through the air.
Similar to other illnesses that cause diarrhea, hamsters with colibacillosis may lead to abdominal pain and depression. Infected hamsters may have profuse watery diarrhea that is foul smelling; some may even develop fluid buildup in the abdomen.
Colibacillosis is an infection caused by the E. coli bacteria. Young and newborn hamsters are more commonly infected with the bacteria due to their poorly developed immune systems, though any hamster living in unhygienic or substandard living conditions can develop the infection. E. coli can be found in contaminated food and/or water; it may even be airborne.
Your veterinarian may suspect colibacillosis by observing the clinical signs exhibited by the hamster. However, an examination of the feces and blood is necessary to confirm the presence of E. coli.