Dental Disease In Rabbits
By Maxine K.
Dental disease is one of the most common, stressful, and expensive problems for domestic rabbits today. And it may be hard to identify.
Rabbits are prey animals. They tend to hide their illnesses, so they may not exhibit any outward signs of distress. A good understanding of how your rabbit’s teeth are designed to work — along with a yearly wellness check by a rabbit-savvy veterinarian — can help you detect dental issues early.
The Whole Tooth
Rabbit teeth grow constantly, nearly one-half of an inch every month, to accommodate a steady diet of grasses, weeds, leaves, and branches. These tough and fibrous plants wear down teeth, so rabbits and other herbivores’ teeth need constant growth to replace what is lost by chewing.
A healthy rabbit has 28 teeth, including six incisors: two big ones on top; two tiny “peg teeth” behind the upper incisors; and two big ones on the bottom.
The incisors cut food into manageable pieces in a scissoring action, upper incisors in front of the lowers, to slice through vegetation.
Molars, or cheek teeth, make up the rest of a rabbit’s teeth. The edges of the molars meet at a slight angle and the jaw moves from side to side to crush the food. They grind food into a fine “mash” that is swallowed and sent down the GI tract for further processing.
All rabbit teeth are very long, but the majority of each tooth is buried inside the bones of the jaws. The small amount of tooth exposed above the gumline is called the crown. The portion below the gumline is the root. Improperly aligned teeth, also called malocclusion, can lead to overgrowth, wounds in the mouth, or abscesses.
Hay All Day
Hay is the single most important component of your rabbit’s diet. It contains the necessary fiber and requires a great deal of chewing.
Make sure to offer your rabbit a daily variety of hays. Different hay textures require different chewing mechanisms to help wear down those ever-growing teeth.
Limit the amount of pellets you feed your rabbit to help encourage more hay consumption, rather than filling up on less fibrous food.
Signs of Dental Disease
Contact your rabbit vet immediately if your rabbit exhibits any of the following signs:
- Decreased appetite, weight loss
- Saliva or food build-up under chin, near lips, or on the inside of the front legs
- Reluctance to eat hard foods like hay
- Stinky Breath
- Lump on the outer cheek, under the eye
- Lump under lower jaws (lumps start small, but can get very large)
- Discharge from cheek or chin/lower jaw area
- Incisors that are uneven (gently lift upper lip to check incisors). If uneven incisors are present, there is a very good chance that the cheek teeth are abnormal as well.
Abscesses
Facial abscesses are the most common form of rabbit dental disease. Unlike abscesses that form in cats and dogs, a rabbit’s facial abscess does not rupture on its own and drains infrequently. Instead, it tends to puncture the bone of the rabbit.
Tooth elongation is the most common cause of tooth root abscesses in rabbits. The cheek teeth can become spiked and erode, or gradually wear into the soft tissue near the teeth, allowing abscess-causing bacteria to enter the gums.
Tissue damage can also lead to the formation of an abscess.
Treatment for an abscess can usually be done on an outpatient basis, unless the rabbit has large abscesses or wounds which may get infected.
Some animals may require long-term pain therapy and management, consisting of non-steroidal anti-inflammatory drugs for inflammation control and to help reduce pain. (Needle aspiration can be used to help drain excessive fluids.)
Fractures
Fractures are serious injuries that can lead to other problems, including damage to root vessels and nerves (and resulting in abnormal tooth growth) as well as abscesses. Incisors may fracture during a fall or when a rabbit sustains some other head injury.
Overgrown teeth are more prone to fracture. In addition, a tooth may fracture during improper dental treatment. It should be noted that most disease of the incisors is secondary to disease of the molars.
Malocclusion
Malocclusion is a fancy name for “misaligned teeth.” Examples in humans are overbites and underbites that may be corrected with braces.
In rabbit malocclusion, the bun’s upper and lower teeth are misaligned so that the normal process of chewing does not wear down the rabbit’s teeth. This can lead to jaw infections and/or weight loss from the bun not being able to eat properly.
The top incisors may grow inwards towards the mouth and the bottom ones grow outwards like elephant tusks.
Malocclusion in rabbits is either inherited (hereditary) or acquired.
- Inherited malocclusion is more likely to happen with dwarf breeds of rabbits. They have been bred with small heads so the rabbit’s teeth may not sit correctly in their small jaw.
- Acquired malocclusion happens when the teeth:
- are not ground down over time, or
- have an altered alignment due to an accident, or even excessive pulling on the wire of a cage.
If left untreated, malocclusion can be extremely dangerous for your bunny as it can prevent him from eating. Even 1-2 days of not eating is serious.
If you suspect that your rabbit’s teeth are misaligned, contact your vet immediately.
If you have a bun with malocclusion:
- pay close attention to its teeth and mouth,
- provide lots of things to chew on in addition to hay (apple branches, chew sticks etc.) and
- monitor its weight carefully.
In severe cases, surgery to remove the teeth may be an option. When cheek teeth are not wearing evenly, they can form spurs or spikes that can lacerate the rabbit’s tongue, cheeks, and other soft mouth tissue.
As a rabbit tries to avoid use of a particular tooth, abnormal pressure is put on other teeth and the uneven wear becomes even greater. In addition, an abscess may form in the soft tissue.
Traumatic Injury and Changes in Jaw Formation
Traumatic injury and changes in jaw formation are two additional causes of rabbit dental disease. Bunny parents should do everything possible to ensure their rabbits’ safety against such trauma.
Even seemingly small “injuries” can occur, change jaw formation, and negatively affect teeth alignment. For example, a caged rabbit who pulls or chews on the metal enclosure can suffer damage because the action can change teeth alignment. Providing more play and runaround time may reduce the rabbit’s frustration at being caged and stop the behavior.
Loss of Bone Density
Loss of bone density is a dental disease that can develop as a rabbit ages. Teeth can become looser in their sockets, and this can cause uneven wear.
Rabbit teeth do not have true roots, but the bases of the teeth can become infected when the teeth are loose, as bacteria from the mouth travel downwards along the gumline.
Swelling almost anywhere along the lower jaw or upper bones of the mouth can signal an infection that requires antibiotic treatment or possibly even surgery.
If you have an elderly bun with any signs of dental disease, ask your veterinarian to do a complete oral exam including head radiographs to detect the extent of the problem and the appropriate course of treatment.
And, remember, your rabbit may not show any signs at all, so regular vet checkups are critical.
Vetting a Veterinarian
It is important to find a doctor who has rabbit experience. Veterinarians who lack sufficient training and experience may misdiagnose problems or just not treat the problem as aggressively as is needed for the best outcome.
Many dental issues can be managed with the help of a veterinarian who is experienced with performing rabbit tooth trims.
A full dental examination requires a general anesthetic or heavy sedation and should include x-rays of the skull. This is the only way for the vet to ensure that he/she has seen and examined every bit of the teeth, tongue, lips, cheeks and gums.
Search for a vet at the Association for Exotic Mammal Veterinarians website; or contact Friends of Rabbits (FoR) for a referral.
Edited by Frank D.