Rodents are one of the few creatures in the Animal Kingdom actually classified by their teeth- a single pair of growing incisors in both the upper and lower jaw that must be kept short by gnawing. Modern rodents are the largest and most diverse of the mammalian order, with 33 families, 481 genera and 2,277 species recognized.
Anatomy of Rodent Teeth
Almost all rodents share the characteristic of dentition (the development of teeth and their arrangement in the mouth) highly specialized for gnawing. The incisors, the big front buckteeth we are so familiar with when envisioning rodents, grow continuously. The anterior (front) and lateral (side) surfaces are covered with enamel, but the posterior (back) is exposed dentin. While the rodent gnaws, the softer dentin wears away leaving the enamel edge like the blade of a chisel. Ever been bitten by your pet guinea pig? Yeah, it hurts, and that’s because their teeth have a very sharp blade-like edge. Rodents don’t have canines like many other mammals, and have a diastema (large gap) between their incisors and premolars. Their incisors are incredibly versatile and are used for a range of functions such as cutting through wood and rope, biting through the skin of fruit, prey capture or defense, depending on the species.
The Dangers of Rodent Teeth
Rodent incisors can be dangerous to even themselves, if they are not able to or allowed to gnaw regularly. Because their front teeth grow constantly, if a rodent was unable to gnaw, those teeth would grow and grow until the either curl around and begin piercing through the jaw they extend from, or they continue growing straight up and eventually pierce through the opposite jaw. All rodent’s incisors continuously grow, but in some, their cheek teeth (the premolars and molars) also grow constantly. For guinea pigs and chinchillas their diet helps to keep their back teeth from growing to long. If the teeth do grow too long, they can pierce through the cheek or tongue and cause gum problems.
Other Dental Concerns For Your Pet Rodent
Dental disease is the most common problem in most rodents. It is linked to a discomfort while eating, and some rodents stop eating all together. Weight loss is inevitable. Dental disease encompasses a wide range of problems including overgrown incisors and tooth root abscesses. Rodent’s, however, rarely suffer from cavities and never need fillings.
Malocclusions are another dental concern for rodent teeth. This problem refers to the misalignment of the upper and lower teeth. When the top and bottom teeth do not meet properly, there is an uneven wearing of the teeth. This can result in long, sharp teeth in the back and overgrown, possibly dull incisors. Maloccluded incisors can appear tusk-like severely overgrown cases. If the back teeth do not line up properly, they can become chipped, broken and sharp which may result in a cut tongue, gums and cheeks.
Tooth root elongation can also become a problem for guinea pigs and chinchillas on a low roughage diet. Pellets, grains and most vegetation are not enough to wear down the cheek teeth and root extension can occur. Bumps under the jaw will form when this happens. Upper teeth can also experience root extension, but instead of the tell-tale bumps, they can cause eye problems such as excessive tearing, and respiratory complications. This is an irreversible dental problem and in most cases, will result in the death of the animal, either through euthanasia or by way of a painful experience.
Tooth root abscesses are another common, and serious, problem with rodent teeth. Most of the abscesses that occur can not be completely removed and recurrence is typical. Treatment consists of extraction of the affected tooth and aggressive surgical debridement of the affected tissue. If this is done, it usually results in long-term follow-up care.
Rodents have a long standing history of being seen as pests. But there are several species we consider as pets; hamsters, guinea pigs, mice, rats, chinchillas and gerbils, and with that in mind their human owners need to recognize the importance of dental maintenance and hygiene, just as they would a cat or dog. If we want our pets to stay healthy and happy, we need to see to their dental needs, making sure they have everything they need to keep their teeth in good health. Before you adopt your rodent counterpart, be sure you know what their natural diet would be so you can be sure to provide it to them on a regular schedule.