Health Care for Hamsters

General Information

Hamsters are small, virtually tail-less, velvet-furred rodents, possessing enormous check pouches. They originated in the Middle East and Southeastern Europe. The most common and popular, both as a pet and as a laboratory animal, is the golden or Syrian hamster. A number of color and hair-type varieties of the golden hamster exist including cinnamon, cream, white, and “teddy bear” (the long-haired variety). An interesting fact is that the majority of the hamsters sold as pets or used in research are the descendents of three litter mates that survived capture and domestication in 1930.

The check pouches are a relatively unique anatomic feature of the hamster. They are actually a cavernous out-pouching of the oral (mouth) cavity on either side, extending along side the head and neck to the shoulders. The function of these pouches if for food storage and to allow the hamster to transport food from the point at which it is gathered to the hamster’s den or nest, into which the cheek pouches are emptied. The food is then eaten at he hamster’s leisure. Hamster owners not familiar with these check pouches, and seeing them fully distended for the first time often panic, thinking they represent tumors or abscesses.

Another relatively unique anatomic feature of the hamster is the presence of paired glands within the skin over the flanks. These appear as dark spots within the hair coat and are much more obvious in males than females. These glands are used by hamsters to mark their territory and have a role in sexual behavior.

Hamsters are extremely popular pets today because of their availability and affordability, their small size and cuddlesome appearance, their docile temperaments, and because of their relatively clean habits. They are not terribly long-lived which can be disconcerting to owners (especially children).

Handling-Restraint

Hamsters handled frequently from a very young age usually remain docile and rarely bite. Those with docile temperaments and a history of not biting can simply be picked up by using one or both hands and then held in both hands or with one held against the body.

Many hamsters have pugnacious and untrustworthy personalities, often resulting from a history of rough handling or being suddenly disturbed or awakened. Hamsters whose personalities are not fully known must always be approached cautiously. A glove or small towel can be used to pick up these hamsters or they can be encouraged to crawl into a small container and be removed from their enclosure in this fashion. They can also be picked up and restrained by grasping a large amount of skin behind the head. It is imperative that as large an amount of skin as possible be grasped between the thumb and index and middle fingers because their skin is so very loose. In fact, hamsters can literally turn nearly all the way around within their skin and bite a handler if this caution is not heeded!

Housing

Proper, adequate housing is a major factor in the maintenance of a healthy hamster. Hamsters can be housed within enclosures made of wire, stainless steel, durable plastic or glass. The latter three materials are preferred because they resist corrosion. Wood and similar materials must not be included in the construction of enclosures because they are difficult to clean and these materials cannot withstand the destructive gnawing of the occupant(s). Many pet stores sell durable colored plastic enclosures which include attached horizontal and vertical tubes through which the resident hamster can crawl for exercise. These are very suitable enclosures for hamsters.

The construction and design of the enclosure must ensure that the resident cannot escape. This is an especially important consideration because hamsters are proficient “escape artists”. In fact, once free of their enclosure, they are very difficult to find and rarely return to it. A hamster with “free-roam” of the house is a real liability because it will chew and gnaw on electrical and telephone cord and household furnishings. The enclosure must also be free of sharp edges and other potential hazards.

The enclosure must be roomy enough to allow the resident(s) to pursue normal activities and breeding activity, if the latter is desired. One reference recommends at lest 2 square inches of floor area per hamster and a cage height of at least 6 inches.

Hamsters are primarily nocturnal (night-active) although they may exhibit relatively short periods of activity throughout the day. During their active period, hamsters will eat and exercise. Hamsters seem to especially enjoy exercise wheels and other means by which they can exert themselves. The plastic enclosures equipped with horizontal and vertical tubes/tunnels mentioned above are very popular and highly recommended for this reason. Hamsters seem to really enjoy running through them. They also enjoy tin cans opened at both ends and boxes with multiple openings through which they can crawl.

Pet hamsters are usually housed singly. Sexually mature females must not be housed together because of their inevitable aggressiveness towards each other. Breeding females are larger than males and tend to be aggressive towards them. For this reason, males must be removed from the enclosure as soon as breeding has been completed.

Hygiene

The general rule of thumb is the enclosure and all cage “furniture” must be cleaned and disinfected at least once weekly, but depends on the material the cage is made of and the number of ferrets in the cage. The food and water containers must be cleaned at once a day. We suggest that more than one set of containers be maintained and the “used” set be washed in a dishwasher, if possible. A vigorous scrubbing of the enclosure and “furniture” with hot water and soap and a thorough rinse must be followed by the use of a disinfectant.

Food & Water

Good quality food, and fresh clean water must be readily available at all times. The exact nutritional requirements of the hamster are not known. In the wild, they are omnivorous, feeding on plants, seeds, fruit and insects. Pet hamsters are most nutritiously and most conveniently fed commercial rat or mouse diets containing at least 16 percent crude protein. These foods are usually processed as dry blocks or pellets. These commercial diets can be supplemented with small amounts of dry, sugarless breakfast cereals, whole wheat bread, uncooked pasta, cooked chicken, tuna fish, cheese, fresh fruits and vegetables. The latter two items must be thoroughly washed to avoid exposing pet hamsters to pesticide residues and possible bacterial contamination.

Pet stores sell prepared hamster diets that either are made available in box or bag form. These diets contain large quantities of seeds and items rich in oils. Consequently, if improperly stored, these items become easily rancid. These oil-rich items promote obesity among pet hamsters. These types of foods can be offered as a supplement to the commercial rat or mouse diets mentioned above.

All foods must be provided in heavy ceramic crocks that resist tipping over. The crocks should have high enough sides to keep bedding and fecal material out of the food or the crock be elevated slightly above the bedding.

Water is most easily made available and kept free from contamination by providing it in one or more water bottles equipped with “sipper” tubes. Make certain that the ends of the tubes are positioned low enough to allow all residents within the enclosure (especially juvenile hamsters over one week old) easy access to them. Furthermore, it is essential to make certain that very young hamsters are strong enough to obtain water from these sipper tubes.

Breeding Considerations

Pregnancy is a very short duration: 15 1/2 to 16 days. Before delivery, the female becomes restless and will usually discharge a small amount of blood from her vulva. Litters usually range from 5 to 10 pups. The pups are born hairless and with both ears and eyes closed. They have their very front teeth (the incisors).

Female hamsters with young should be provided with abundant nesting and bedding materials and plenty of accessible food and water, and must not be disturbed in any way during the whelping process. The young should not be touched or handled until they are at least 7 days old, the nest should not be disturbed, and the cage should not be cleaned during this period. Failure to heed this caution (especially with females nursing their first litter) most often results in cannibalism of the young.

An interesting maternal rearing activity may be noted be particularly observant hamster owners, especially if the female with young is excited or disturbed. She will stuff pups into her cheek pouches and deposit them into the nest a short time later when she believes the danger has passed. Occasionally, pups will suffocate as a result of this behavior, especially if the disturbance for which they are being “sheltered” is lengthy.

Young hamsters usually begin eating solid food at 7 to 10 days of age but are usually weaned at about 3 weeks of age. It is most important that solid, pelleted food be soaked and softened and be placed on or rear floor level of the enclosure for easy access by the weanlings. As mentioned above, sipper tubes must be positioned low enough that the smallest of the pups can reach it. Some pups will not be strong enough to extract water from sipper tubes, so owners must be vigilant for this potential problem and provide an alternative water source for them.

Disease

Sick hamsters often become irritable and frequently bite. They are usually reluctant to move about and walk stiffly when forced to do so. Their eyes often look dull and sunken and frequently exhibit a discharge. Sick hamsters often stop eating or greatly reduce their intake of food. Consequently, weight loss is a common symptom (not necessarily an easy one to recognize) of illness in hamsters. Marked weight loss also may result from excessive fluid losses resulting from diarrhea. Sudden onset of intestinal disease (with accompanying diarrhea) is the most common illness of hamsters, especially among those that are in the process of weaning or those that have recently been weaned. The serious dehydration that often results must be recognized immediately and corrected with appropriate fluid therapy at the direction of a veterinarian or death can occur.

The most serious intestinal disease of hamsters is “wet tail”. The bacteria suspected of causing this disease is called Campylobacter, which is also capable of causing equally serious intestinal disease syndromes in other animal species.

This disease most often afflicts hamsters of weaning age (3-6 weeks) but hamsters of all ages are susceptible. Since weaning hamsters and those slightly older are commonly sold in pet stores, wet tail is a fairly common disease among recently acquired hamsters. The long-haired “teddy bear” hamsters are highly susceptible to wet tail. Symptoms include lethargy, inappetence, unkempt hair coat, sunken, dull eyes, increased irritability, hunched posture, very fluidly diarrhea, and a wet soiled anal area and tail. Blood from the rectum and a protrusion of the rectal lining (prolapsed) may be noted in particularly serious cases.

Hamsters suffering from wet tail must be examined and evaluated by a veterinarian immediately. Fluid replacement, oral anti-diarrhea medication and antibiotics will be administered to the patient. Supportive care must include keeping the patient warm, clean, comfortable, and well nourished. Treatment is often unrewarding and death often ensures as soon as 48 hours after the onset of initial symptoms. This disease is not known to be transmissible to man.

Salmonella

Salmonella is capable of causing serious intestinal disease is hamsters under certain circumstances. The reason why this problem is discussed in this handout is that salmonellosis is transmissible to and equally serious in man.

The bacteria is usually acquired by the ingestion of food contaminated with feces containing the organism. Pet hamsters established in homes would most likely become infected via this route. It is because of this fact that fresh fruits and vegetables must be thoroughly washed before they are offered to hamsters. Newly purchased pet hamsters may harbor this salmonella organism, having acquired it from the colony into which they were born. Everyone, especially children should wash their hands after handling hamsters.

Lymphocytic (LCM)

This viral disease must be discussed briefly because it can be transmitted from hamster to humans. Symptoms of this disease in humans include persistent, intermittent fever, headache, fatigue, muscle aches and pains, sore throat, rash and arthritis.

The natural host in the wild for the LCM virus is the rodent population and hamsters would most likely acquire their infection from this source. Because hamsters are almost exclusively indoor pets, the likelihood of them becoming infected with LCM virus is very small. Hamster owners must restrict contact between their pets and wild rodents that may have been orphaned in the wild and subsequently adopted.

Demodectic Mange (Demodecosis)

Demodectic mange is a common external parasite problem of hamsters caused by mites who reside within the hair follicles and certain glands of the skin. Their presence in this location causes dry, scaly skin and significant hair loss, especially over the back.

This disease is rarely a problem by itself. In fact, Demodectic mange of hamsters if frequently associated with long-standing, debilitating disease (especially those involving the kidney[s]) of other causes.

Hamsters exhibiting hair loss should be examined and evaluated by a veterinarian as soon as possible. The doctor will need to do a skin scraping and examine it under the microscope. The presence of mites in the scraping confirms the diagnosis. Treatment for this disease is possible but hamster owners must be aware that the patient could very well possess an underlying disease problem for which there is no practical treatment or cure.

Intestinal Parasites

Hamsters frequently harbor tapeworms within their small intestines. Heavy infection may cause weight loss. Lighter infections usually go undetected unless pieces of the worm pass out of the hamster’s rectum or appear in the feces.

This parasitism is important to discuss because people can become infected with the same organism. Transmission of tapeworms to uninfected hamsters (or humans) occurs when feces harboring tapeworm eggs are inadvertently ingested. This underscores the importance of restricting access to hamsters and their enclosures by very young children. All encounters between them must be carefully monitored.

Hamster owners suspicious of this parasite problem must submit a fecal sample to a veterinarian for analysis. Presence of tapeworm eggs in the sample (noted microscopically) confirms the diagnosis. Treatment is possible and will be instituted at the direction of the veterinarian.

Pinworms are tiny specks that can sometimes be seen around the rectum of the hamster. They are not transmissible to people but can be disconcerting when found by the owner. Again everyone should wash their hands after handling a hamster.

Hamsters are very cute, cubby creatures and can be very entertaining companions.

This health care information was compiled by Marilyn Lieb, D.V.M.