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hamster Care Guide

Hamster Diseases and Conditions Requiring Veterinary Care

Download Hamster Disease Care Guide – PDF

Disease Prevention

Hamsters are affected by only a few naturally occurring diseases.  However, they are susceptible to a host of diseases from other animals and even people.  Teddy Bear and color varieties other than the golden hamster tend to be more sensitive to disease.

Because hamsters are nocturnal and not closely observed, many illnesses go unnoticed until too late for medical help.  Frequent inspection of all hamsters by the owner is paramount to early detection of disease.

Sick hamsters often become irritable and frequently bite.  They are reluctant to move and walk stiffly when forced.  Eyes often look dull and sunken and may have a discharge.  Sick hamsters often stop eating and may rapidly lose weight.  Weight loss from dehydration (due to diarrhea) is another sign of illness.  (Weight loss and dehydration are very common signs of illness.)  Dehydration will lead rapidly to death. 

Diseases and Disorders

Obesity: Owners who overindulge their hamsters with diets high in nuts and seeds are most often responsible for this condition.  Feeding junk foods like pizza, cookies, candy and donuts increases the risk of obesity and destroys the benefits of feeding a balanced diet.

Overgrown Incisors:  The front teeth (gnawing teeth) of hamsters grow continually for the life of the individual.  Normal wear occurring between the upper and lower teeth usually keeps the teeth at the proper length.  However, hereditary abnormalities of the teeth or jaws, injury to the jaw(s) or disease of the jaws or teeth can cause an improper meeting of the teeth.  This malocclusion results in the overgrowth of one or more of the incisors, causing subsequent injury to the mouth.  Overgrown incisors make eating difficult or impossible.  The teeth are trimmed as needed by the veterinarian.

Symptoms:  Weight loss, excessive drooling, bleeding from the mouth, incisor visible outside the mouth, difficulty eating, pawing at face.

Tumors: Cancerous tumors are common in hamsters.  Both male and female hamsters develop cancer, but it is more likely in females due to the large number of tumors arising from the female reproductive tract.  Cancers involving hormone-producing organs (thyroid and adrenal glands) are among the most common variety of cancers.  These cancers cause loss of hair, behavioral changes and other signs.  Some of these tumors can be removed with surgery under general anesthesia.

Tumors are more easily removed when small than when left alone to grow large.  Even benign tumors can cause significant damage to the hamster if the tumor is large enough.  Biopsy of the tumor can be used to determine the type of cancer and the long-term outlook for the pet.

Abscesses, lacerations & ulcers: Many types of bacteria enter through bite wounds or other injuries and cause abscesses or ulcers.  Antibiotic therapy is usually curative, but surgery may be required to lance and repair large abscesses or close lacerations.  Rodent pus is thick and resists simple draining.  Combinations of antibiotics and surgery seem the best choice.

Abscesses of the cheek pouch occur when bedding material or food punctures the lining of the mouth.  The swelling caused by the abscess is indistinguishable from the normal swelling associated with a pouch full of food.  However, the abscess and swelling will persist after food and bedding have been removed.  Persistent enlargement of one or both pouches is a sign of a problem.

Wet Tail: The most serious intestinal disease of hamsters is “wet tail,” a bacterial infection of the intestines.  The disease often afflicts hamsters of weaning age, but can occur in hamsters of any age.  Since most hamsters sold in pet stores are of weaning age or slightly older, wet tail is very common.  Teddy bear hamsters are particularly susceptible.  The disease is difficult to treat and is frequently fatal in 48 hours after the onset of symptoms.  This disease is not transmissible to humans.

Symptoms:  Poor appetite, lethargy, hunched posture, unkempt hair coat, watery diarrhea, wet/soiled anal area, rectal prolapse.

Salmonellosis:  Several species of the bacterium, Salmonella, cause serious intestinal disease in hamsters and people.  The bacterium is often acquired by eating food contaminated with the organism.  For this reason, fresh fruits and vegetables offered to hamsters require thorough washing before use.  Newly purchased hamsters may bring the organism with them from an infected colony where they were raised.  Salmonellosis may cause long-term illness and weight loss or sudden death.  Antibiotic therapy may be attempted, but treatment brings mixed results.  Because of the human health hazard, euthanasia may be recommended.

Symptoms:  Gradual weight loss, unkempt hair coat, and sudden death.

Trauma:  Hamsters are easily injured.  They are frequently dropped when handled or after they bite.  A fall of just twelve inches can result in a broken spine — for which there is no practical treatment.  Free-roaming hamsters often are stepped on, closed in doors, kicked or injured in dozens of other ways.  Exercise balls (a plastic ball in which the hamster is placed for exercise) are responsible for many injuries or deaths when they are kicked or roll down stairs with the hamster inside; the balls also become traps when the hamster is forgotten (often by children) and left to die of over-heating, starvation or dehydration.

Injured hamsters require immediate veterinary attention.  Splinting of broken limbs is difficult as the bones are small and the hamster is an accomplished chewer — few casts or splints can stand up to hamster teeth.

Bladder Stones:  Hamsters are susceptible to stones within the urinary tract.  Stones are frequently associated with infection of the urinary tract.  Antibiotic therapy and surgery are corrective procedures.

Symptoms:  Frequent urination (difficult to detect), straining to urinate, blood in the urine, increased water consumption, listlessness, and poor appetite.   

Parasitic Infections

External Parasites: 

Mites (demodex) are microscopic, live within hair follicles and cause scaly, dry skin and significant hair loss.  The mites are not a disease by themselves, but are often associated with an underlying disease (frequently kidney disease).  Consult us if you suspect mite infestation.  One or more scrapings will be made of the skin to locate and identify the mites.  Treatment to eliminate the mites is available, but the underlying disease may not be treatable.

Symptoms:  Mild to severe scratching, hair loss, skin ulcers, dry skin.

Internal Parasites:

Tapeworms and Pinworms: The most common intestinal parasites of hamsters.  Unless present in large numbers, they often go unnoticed.  Microscopic examination of the stool will determine the presence of the parasites. Once found, appropriate therapy will rid the pet of the parasites.  However, pinworms are particularly difficult to eliminate from rodents. There is a potential for transfer of intestinal parasites from the hamster to humans.  Instruct anyone (especially children) who handles the hamster to thoroughly wash their hands after handling.

Symptoms:  Inactivity, weight loss, poor appetite, constipation, excessive licking of the rectal area, chewing on the base of the tail or rectal area.