Proliferative Ileitis (Wet Tail)

The most commonly encountered bacterial infection recognized in hamsters is “wet tail”. The precise cause of the disease is not fully understood, but underlying infections with the bacteria Campylobacter fetus subspecies jejuni have been reported.
Campylobacter sp. are responsible for serious intestinal diseases in other animal species such as swine, dogs, ferrets, primates and even humans. Although this agent is suspected to be an underlying cause of this syndrome, pure cultures of the bacteria cannot reproduce the disease, suggesting other predisposing factors or agents. Such contributory factors include improper diet, sudden dietary changes, overcrowding and other stresses.

This disease most often affects weanling hamsters between the ages of 3 to 6 weeks, but hamsters of all agesare susceptible. Since this is the age at which most hamsters are sold, this is a common disease encountered in recently acquired pets. The longhaired “teddy bear” hamster seems to be more vulnerable than the other varieties.

Death may result within 1 to 7 days after the onset of watery diarrhea. Other signs include matting of the fur around the tail, unkempt hair coat, and hunched stance, loss of appetite, dehydration, emaciation and irritability. Blood from the rectum and rectal prolapse may be noted in some serious cases. This is a very serious disease, with death being the most likely outcome. Due to the severity of this disease, any hamster exhibiting these signs must be examined by a veterinarian as soon as possible. Antibiotics, fluid therapy and anti-diarrheal medications will be administered to the patient. Supportive care will also be instituted. Despite best efforts, treatment is often unrewarding with death occurring within a couple days in many cases.

Hair Loss (Alopecia)

Hair loss can occur for a number of reasons in hamsters. This loss of hair can be due to both disease and non-disease conditions. Continual rubbing on feeders or sides of the cage as well as barbering and hair chewing by cage mates are examples of non-disease causes of alopecia. Infestation with mites is one of the most common infectious causes of patchy alopecia and scaling in hamsters. Other conditions that lead to hair loss include adrenal tumors, thyroid deficiency and chronic renal disease. Some of these conditions may be correctable, while others are not.

Demodex mites are the most common external parasite causing problems in hamsters. The mite lives within the
hair follicles and certain skin glands of their host. The presence of these mites results in dry, scaly skin and subsequent hair loss, especially over the back and rump. This disease is rarely a problem by itself. Demodectic mange in hamsters is often associated with chronic, debilitating diseases or other underlying problems. For this reason, a thorough examination must be performed on any hamster presented with mites. To confirm the presence of mites, the veterinarian may perform a skin scraping for microscopic observation. Treatment for the mites is often possible, but remember that there may be another problem, often more severe, underlying this one which must also be addressed.

Geriatric Conditions

Hamsters tend to have relatively short life spans when compared with other species. The average life expectancy of a hamster is between two and three years of age. For this reason, spontaneous aging diseases are not uncommon in these animals, typically after the age of one year. Two of the most common geriatric diseases of hamsters are amyloidosis (protein deposition in various organs) and cardiac thrombosis (blood clots in the heart). Treatment of these conditions involves managing clinical signs since cures are not possible. A diagnosis of virtually any geriatric disease carries with it a poor prognosis.

Amyloidosis is a condition whereby proteins produced by the body are deposited in various organs, primarily the liver and kidneys. Kidney and liver failure often occurs as a result of this protein deposit. Many other organs are also affected and the changes are irreversible. Signs of this condition include swollen abdomen, urinary problems, dehydration, poor appetite and rough hair coat. Supportive care is the only treatment since this condition is eventually terminal.

Blood clots within the heart occur at a relatively high frequency in older hamsters. This condition is known as cardiac thrombosis and typically occurs in the left side of the heart. Many factors are involved in the formation of these clots including clotting disorders, heart failure, circulating bacterial infection and amyloidosis.

Many other old age diseases occur in hamsters over the age of one year. Liver and kidney disease is not uncommon in middle age to old hamsters. Other conditions commonly encountered are gastric ulcers, tumors and dental disease.