Enteritis is a very common problem in hamsters. One severe form of enteritis is proliferative ileitis, or “wet tail”, to which the Golden hamster is very sensitive. The mortality rate among affected animals is about 90%. This form of enteritis is caused by the bacterium Lawsonia intracellularis and is spread through the oro-faecal route. The incidence is highest among young animals of 3-8 weeks old and it seems that long-haired varieties are more sensitive. Poor hygiene, dietary errors, stress and overcrowding are predisposing factors.
The clinical signs include watery diarrhoea that soils the fur (from which the name “wet tail”), anorexia, a sagging posture, lethargy and death within a couple of days. Peritonitis, invagination and rectal prolapse may occur in the less serious cases. Thickening of the intestinal loops may be felt by palpation. The diagnosis may be suspected on the basis of the clinical signs, but confirmation can only be obtained by post-mortem histological examination of the bowel.
Treatment is rarely successful, but consists of immediate initiation of antibiotic therapy with tetracycline, neomycin (20 mg/kg) or a combination of enrofloxacin and trimethoprim-sulphamethoxazole. Fluids, such as Ringer’s lactate or physiological saline, should be injected subcutaneously or intraperitoneally, at a dose equivalent to 10% of the body weight. Predisposing environmental factors must also be corrected.
Other bacteria may be involved in enteritis in the hamster. Clostridium piliforme, responsible for Tyzzer’s disease, can cause acute diarrhoea and death. This is an obligate intracellular bacterium that cannot be cultured; the diagnosis can only be made from post-mortem histological studies. The treatment is the same as that for proliferative ileitis and the mortality rate is very high in this case too.
Salmonella is rarely a cause of diarrhoea in hamsters. Since salmonellosis is a potential zoonosis, it is recommended that affected animals are euthanized.