Care of Hamsters
Hamsters are peculiar little rodents with large cheek pouches and short stubby tails. They have gained popularity as pets and research animals since the 1930’s. The Syrian hamster’s (golden hamster) wild habitat extends through the Middle East and Southeastern Europe. In 1930, a litter of eight baby hamsters was taken to Israel and raised as research animals. Virtually all domesticated hamsters sold in the pet trade and research are descendents of three of the survivors of this litter. Hamsters were first introduced to the United States in 1938.
Since their domestication, several color and hair coat varieties of the Syrian hamster have arisen through selective breeding. The three basic groups that now exist include the common “golden” hamster, colored short-haired “fancy” hamster, and long-haired “teddy bear” hamster. All three varieties are popular as pets.
On occasion, one may encounter other species of hamsters, but these are much less common than the Syrian hamster. The smaller, dark brown Chinese hamster (dwarf hamster) is often used in biomedical research, and they are sometimes acquired as pets. These hamsters are recognized for their small size, dark brown color, and black stripes over their backs. The Armenian (grey) hamster and European hamster are two other species occasionally used in research, but seldom kept as pets. The following information pertains particularly to the Syrian, or golden hamster, since they are by far the most popular.
The best place always to buy a hamster is directly from a private or hobbyist breeder, but this may not always be possible and therefore many hamster owners buy their first hamster from a pet shop.
DIET
As with any pet, good quality food and clean, fresh water must be provided at all times. The precise nutritional requirements of hamsters have not been fully determined. In the wild, hamsters feed on plants, seeds, fruit, and insects. Current recommendations for feeding pets are pelleted rodent food containing 15% - 20% protein. These feeds are typically processed as dry blocks or pellets designed for rodents. Seed diets are also “formulated” and sold for hamsters, but these diets should only supplement the basic rodent pellet. Seed diets contain high levels of fat which can easily become rancid if improperly stored. In addition, when fed alone, these diets often lead to obesity and potential nutritional deficiencies. Other supplements to the diet may include sugarless breakfast cereals, whole wheat breads, pasta, cheese, cooked lean meats, fresh fruits, and vegetables. It is important that all of these supplements are fed in moderation, as treats, for the hamster. Hamsters eat approximately 12 grams of food daily, and usually consume the majority of this at night. Hamsters are like little pack rats and often hoard their food in a corner of their cage, making it seem as though they eat a lot more than they really do.
Water is easily provided in water bottles equipped with sipper tubes. This method also helps keep the water free from contamination. Always make sure that the tubes are positioned low enough to allow the hamster easy access. Juvenile hamsters need special consideration as they may not be strong enough to use the sipper tube, or big enough to reach it. The average hamster drinks approximately 10ml of water per 100g of body weight (average adult weight is 100g). Although this amount is only a fraction of the total bottle volume, the bottle should be changed daily to provide fresh water.
HANDLING
Hamsters handled frequently from a young age usually remain docile and seldom bite. These animals or a docile nature can be gently picked up by cupping in one or both hands and held against one’s body. Beware that even docile hamsters may bite if surprised or abruptly awakened from sleep.
Other hamsters, however, may not have received a lot of attention and handling throughout their lives, and thus may be more apprehensive and aggressive. Any animal whose personality is not fully known must be approached cautiously. The use of a small towel or gloves can assist the handler in capturing and restraining such a pet. Another method of capture involves coaxing the animal into a container (such as a can or tube) can be restrained by grasping a large amount of skin at the scruff of the neck. As much skin as possible must be grasped using this method, because their skin is very loose. If lightly scruffed, the hamster can easily turn around within its skin and bite the handler.
HOUSING
Several types of cages are available which are suitable for housing hamsters. Many of these units come equipped with cage “furniture” such as exercise wheels, tunnels, and nest boxes as added luxuries. Such accessories, as well as sufficient litter depth within which to burrow, are desirable for the pet’s psychological well being. Cages should be constructed with rounded corners to detour chewing. Hamsters will readily chew through wood, light plastic and soft metal; so recommended caging materials are wire, stainless steel, durable plastic and glass. Beware that glass and plastic containers drastically reduce ventilation and can lead to problems with humidity, temperature, and odor concentration. Theses materials make suitable cages when at least one side of the enclosure is open for air circulation. In addition, make sure that the enclosure is escape proof, since these little rodents are known escape artists.
Hamsters do very well in solid bottom cages with deep bedding and ample nesting material. Bedding must be clean, non-toxic, absorbent, relatively dust free, and easily acquired. Shredded paper or tissue, wood shavings and processed corn cob are preferred beddings. Be sure that the wood shavings and ground corn cob are free from mold, mildew, or other contamination before using. Cotton and shredded tissue paper make excellent nesting materials.
Adult hamsters require a minimum floor area of 19 square inches and a cage height of 6 inches, though a larger cage is recommended. Female breeding hamsters require much larger areas. Optimal temperature range for hamsters is between 65˚ to 80˚, with babies doing best between 70˚ to 75˚. The relative humidity should be between 40% and 70%. Twelve hour light cycles are preferred, with hamsters being more active during the night.
Pet hamsters are generally housed singly. Mature female hamsters tend to be very aggressive towards one another and should never be housed together. Females are also larger and more aggressive than males. Males may also fight when housed together, but tend to be less aggressive than females.
As a rule of thumb, the cage and accessories should be thoroughly cleaned once to twice weekly. An exception to this schedule is when newborn babies are present, then wait until they are at least two weeks old. Other factors that may require increased frequency of cleaning are the number of hamsters in the cage, the type of bedding material provided and the cage design and size. Cages are sanitized wit hot water and nontoxic disinfectant or detergent, then thoroughly rinsed. Water bottles and food dishes should be cleaned and disinfected daily.
INFECTIOUS CONDITIONS
Proliferative Heitis (Wet Tail)
The most commonly encountered 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 spp. 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 ages are susceptible. Since this is the age at which most hamsters are sold, this is a common disease encountered in recently acquired pets. The long haired “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, unkept hair coat, 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.
Due to the severity, 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 all the best efforts, treatment is unfortunately often unrewarding.
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, or hair chewing by cage mates are examples of non-disease causes of alopecia. Infestation with Demodex 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 the host. The presence of these mites result 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, more severe problem underlying this one which must also be addressed.
Old Age Diseases (Geriatric Conidtions)
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 deposition. 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 diseases.
HAMSTER FACTS
Average Life Span……………………………………………………2-3 years
Adult Body Weight…………………………………………………..100-150 grams
Environmental Temperature Range………………………………….65˚ to 80˚
Relative Humidity Range…………………………………………….40% to 70%