Abnormality of Incisor Teeth in Rabbits

Since a rabbit’s teeth continue to grow throughout its life, if malocclusion occurs, the overgrowth can cause enough pain to stop a rabbit from eating. While it can be treated if caught early enough, if left to become too overgrown, these incisors can grow outside of the mouth, or curl back in to grow through lips, mouth tissues, and even into the nasal cavity, making eating more difficult. This abnormality can also result in infections, abscesses, abnormal root growth, misalignment of the jaw, severe bone destruction as roots grow into the jaw and nasal cavities, and fractures in the teeth themselves.

The incisor teeth of rabbits are located in the front of the jaw, with a large set in the top jaw, in front of a small set, called peg teeth, and another large set on the bottom jaw. Normal rabbit incisors are aligned and allow for a natural grinding down of those teeth during eating. But incisors that are not aligned correctly can become overgrown, and cause a myriad of problems.

Symptoms of abnormal incisors in your rabbit may include:

• Excessively long incisors
• Change in eating habits, such as decreased appetite
• Selective eating 
• Inability to pick up food
• Drooling
• Wet and matted fur on mouth, chin, chest and front legs
• Fur loss in wetted areas
• Epiphora, or excessive tearing
• Increased thirst
• Anorexia
• Abscesses and infections in the mouth
• Weight loss
• Dried feces around anus
• Teeth are white, dull, and have horizontal grooves (normal teeth are yellow, shiny and have vertical grooves), characteristic of osteodystrophic dental disease
• Sinus issues, such as infections, runny nose, nasal discharge and obstructions to nasolacrimal duct
• Eye issues, such as infections, bulging eye, decreased eyesight, eye discharge and eye injury
• Pain
• Depression
• Lethargy
• Sitting in a hunched position often
• Visible swelling in the mouth or face
• Lumps under chin
• Decreased grooming
• Symptoms of conjunctivitis and dacryocystitis
• Molar or pre-molar malocclusion

Causes of abnormal incisors include:

• Misalignment of teeth and jaw
• Insufficient diet, such as one high in pellets or that doesn’t allow constant chewing
• Genetic predisposition, such as brachygnathism, or a shorter upper jaw, more common in dwarf and lop rabbits
• Vitamin D and Calcium deficiency
• Trauma
• Loss of one incisor, leading to the malformation of the others

After a full physical exam, including the oral cavity, X-rays and CT scans of the skull can be used to further assess the extent of the abnormality. Incisor overgrowth may be accompanied by pre-molar and molar overgrowth, as well as root growth inside of the jaw and nasal cavities. All infections, abscesses and obstructions are noted. Force feeding may be required in severely debilitated animals.

Because malocclusion of the incisors can be indicative of a more serious dental disease, time will be taken to fully analyze the scope of the dental issues involved. All the symptoms leading to the visit will be taken into account and can sometimes point towards an underlying problem. Be sure to report any and all changes noticed in your rabbit prior to your visit, as well as a dietary history.

Treatment is by one of two methods. A veterinarian can regularly clip, file or grind the incisors down during periodic visits, generally every 3-6 weeks. Clipping does run a risk of creating fractures in the incisors that can extend below the gum line, giving bacteria a way in to cause infections that can become life threatening, so filing is generally recommended. Anesthesia can be administered during this procedure to reduce stress. It is highly advisable to never clip or grind the incisors at home. 

In severe cases, surgery to extract the incisors can be performed, providing a more permanent solution. However, once this has been done, a rabbit will lose its ability to cut food, and the owner must cut their pieces of food for them for the duration of their life. Hay and pellets, since these are primarily chewed by the molars, should not be a problem. 

Generally, antibiotics will be administered to stop or prevent infections, and the diet will be examined, and usually altered to encourage a more healthy level of attrition. There may be secondary issues, such as abscesses, infections, and tissue damage that will need to be assessed and treated. Depending on the severity, further surgery may be required, and topical antibiotics administered.

Vitamin D and calcium supplements may be prescribed if a deficiency is to blame. Malocclusion can be indicative of a more serious dental disease, and if present, that will need to be treated as well, through medicine, surgery and lifestyle adjustments.

After any surgery is conducted, pain medications and antibiotics may be prescribed. Keep your rabbit’s environment clean and stress free, and watch for a lack of appetite. You may need to force feed your rabbit to prevent further complications. Generally, your rabbit should be up and about in a matter of days.

To maintain healthy incisor length and prevent reoccurrence as much as possible, be sure to feed your rabbit a natural diet of fibrous foods, such as grasses and hay, while minimizing the amounts of concentrated pelleted food. This encourages more chewing and a natural attrition of teeth. An appropriate diet can also slow dental disease if present. Schedule routine incisor filing when appropriate to ensure the safety and health of your rabbit.

Dental disease is often a lifelong battle, and your veterinarian will discuss appropriate maintenance with you if such a condition is present. To prevent any genetic characteristics predisposing abnormal incisors from spreading, do not breed affected animals.