By Dr. Laurie Hess, DVM, Diplomate ABVP (Avian Practice)
Hamsters are small rodents. The word “rodent” comes from the Latin word “rodere,” which means “to gnaw.” Gnawing is a very important activity for hamsters, as their upper and lower front teeth (known as incisors), are covered by yellow-orange enamel and continuously grow throughout their life. It is critical that these small animals gnaw to wear down their continuously growing front teeth as they grow.
Hamsters also have large, muscular outpouchings of the lining of their mouths (one on each side of their face) called cheek pouches. They use these pouches to transport food, bedding and, occasionally, babies. When filled, cheek pouches look like large sacs that can extend as far back as the shoulder. Hamsters use their front paws to massage food out of the pouch when they are ready to eat it.
Dental Problems in Hamsters
Since their incisors grow throughout life, hamsters commonly develop overgrown incisors that may get so long that they interfere with closing the mouth to eat. Overgrown incisors also can poke into the gums and tongue, causing cuts and bleeding. If both upper and lower incisors overgrow, they may hit each other when the hamster tries to close its mouth, breaking off and causing pain.
Hamsters with overgrown incisors also may chew on the bars of their cages, breaking off their teeth accidentally and causing discomfort when they try to eat. Once incisors are broken off, they may not grow back in at all, or they may grow in crooked. Broken incisors also can cause lacerations of the palate (the hard, bony plate in the roof of the mouth), leading to the formation of an abnormal fistula (or hole) that connects the mouth to the nasal cavity. Hamsters with such oral-nasal fistulas may sneeze and have nasal discharge.
Though it is less common than incisor problems, hamsters can also have problems with their back teeth (known as cheek teeth). Since hamsters’ small mouths and tendency to nip makes it impossible for owners to brush their teeth, food can become impacted between the back teeth, leading to bacterial growth, ulceration of the gums and occasionally tooth root abscesses (infections). Hamsters with cheek teeth issues may have difficulty eating, lose weight and have swollen lower jaws or swellings below or around their eyes.
Cheek Pouch Disease
A hamster’s cheek pouches may become impacted with large pieces of food or cotton/paper bedding that get stuck to the lining of the pouch, such that hamsters cannot massage them out. Impacted cheek pouches often develop into abscesses that appear as large swellings on one or both sides of the face. Occasionally, hamsters will rub so hard to empty their cheek pouches that they evert or turn inside out inside the mouth and then stick out, like a large sac, through the mouth. One or both cheek pouches can evert, and everted pouches may be painful, bleed and interfere with eating.
How to Prevent Oral Problems in Hamsters
To lessen the chance of developing overgrown incisors, pet hamsters should be given small, soft wood blocks or other appropriate wooden chew toys made for small rodents on which they can chew and wear down their teeth. They also should be provided with other forms of enrichment, such as cardboard or wooden boxes in which to hide, exercise wheels in which to run and paper to shred, so that they don’t get bored and chew on cage bars. They should be fed a balanced diet of commercially available, nutritionally complete rodents pellets, supplemented with small amounts of fresh produce, and seed only as an occasional treat. Balanced nutrition in hamsters helps them develop strong bones and teeth, just as it does in people.
To lessen the likelihood of cheek pouch issues, hamsters should be offered small chunks of produce and other foods that are less apt to get stuck in cheek pouches. Hamsters should be provided with fresh water in a sipper bottle and/or bowl daily so that the lining of their cheek pouches stays hydrated and supple and doesn’t stick to food or bedding.
Symptoms of Dental Issues in Hamsters
Your hamster should be monitored daily to ensure that they are eating, passing normal droppings, and don’t have unusual facial swellings or nasal discharge. Hamsters that are losing weight, not passing normal amounts of stool, not eating normally, or that have swollen faces or significant nasal discharge should be examined by a rodent-savvy veterinarian as soon as possible.
Hamsters with overgrown teeth may need to have these teeth trimmed or surgically extracted. Those with tooth root or cheek pouch impactions/abscesses or oral-nasal fistulas typically need surgery, antibiotics, and pain killers to remove impactions/abscesses, close fistulas and treat infection.
Since hamsters are prey species that tend to hide their signs until they are very sick, and since many hamster owners do not handle their pets daily, all pet hamsters should have at least an annual check-up at their veterinarian, just as we have annual examinations by our dentists, to ensure their mouths are healthy.