By Laurie Hess, DVM, Diplomate ABVP (Avian Practice)
Chinchillas’ teeth, like those of other rodents, such as guinea pigs and degus, are open-rooted and grow continuously throughout their lives. Wild chinchillas have evolved this type of teeth to adapt to prolonged chewing on the rough shrubbery and vegetation they survive on in the Andes mountains where they live. Their front teeth — the incisors — can grow as much as 2-3 inches per year!
What Causes Tooth Overgrowth in Pet Chinchillas?
Pet chinchillas typically are not fed the same type of abrasive foods their wild counterparts consume. Instead of eating coarse vegetation, they are generally fed dry pellets that crumble in their mouths, requiring little to no chewing, as well as some hay. Hay consumption encourages chewing but not at the same frequency as that performed by wild chinchillas. Thus, pet chinchillas’ teeth grow as rapidly as wild chinchillas’, but pets don’t spend as much time chewing, so their teeth may grow in faster than they are worn down. Genetic factors as well may predispose to teeth overgrowth. Both incisors and back teeth (or “cheek teeth”) can become overgrown.
Both the portions of the teeth visible in the mouth (the crowns), as well as the parts of the teeth below the gums (the roots) that are not visible inside the mouth, may become elongated. As a result, the crowns visible inside the mouth may look step-like or wavy, while the roots may feel bumpy and irregular when the upper and lower jaws are palpated on the face. The crowns may develop sharp edges and points from irregular wear, causing ulcers and sores on the gums and inside the cheeks. Elongated roots below the gum line may become painful and impacted, like impacted wisdom teeth in people, and ultimately may become infected, evolving into large facial abscesses.
What Are the Signs of Overgrown Teeth in Pet Chinchillas?
If a chinchilla’s incisors are overgrown, they may appear excessively long when the upper and lower lips are gently lifted. Bumpy swellings may be palpable especially along the lower jaw when an owner runs a hand over the jaw from front to back. Even before they show these obvious abnormalities, chinchillas affected with dental problems may simply drool more, eat slower, select out softer or easier to chew foods, or eat less overall. Their fecal pellets may become smaller, drier, and less frequent. Affected chinchillas may gradually lose weight and develop matted fur or fur loss on around their mouths, chins, and front paws from excessing drooling. If impacted teeth roots grow into the tear ducts that run under the skin on their faces, affected chinchillas also may show excessive tearing.
What Should a Chinchilla Owner Do if He or She Notices These Signs?
Owners who observe any of these signs in their pets should have them examined by a veterinarian as soon as possible. Delaying the veterinary visit simply leads to worsening of signs and often a poorer prognosis. A chinchilla-savvy veterinarian will not only perform a thorough physical examination, including a comprehensive oral examination using an oral speculum to look at the cheek teeth, but also take x-rays of the head to see the tooth roots not visible from inside the mouth. Very stressed or active chinchillas that will not allow a speculum examination may need to be sedated for examination and x-rays. Prognosis depends on what the veterinarian finds.
Chinchillas with early disease involving crown overgrowth or sharp points on the crowns, with normal looking roots on x-rays, may require crown reduction, in which the surfaces of the elongated teeth within the mouth are filed down so that crowns are shorter, even, and smooth. More severely affected animals whose x-rays show elongation and impaction of teeth roots may require long term pain medication to lessen discomfort on chewing.
Those animals with advanced disease that have developed facial abscesses require surgical removal of infected teeth and debridement of the abscess, as well as treatment with antibiotics, pain killers, and anti-inflammatories. Very severely affected chinchillas may need to be fed soft foods or even be supplemented with syringe feeding a gruel-like formula to maintain their weight.
Dental problems in chinchillas are lifelong and typically require repeated treatment. Owners of chinchillas with dental problems should be prepared for recurrent trips to the veterinarian and the long-term expense that goes with these visits.
How Can Chinchilla Owners Try to Prevent Dental Issues in Their Pets?
The best way to try to prevent overgrown teeth in chinchillas is to feed them as much hay as possible. Hay is coarse fiber that not only promotes prolonged chewing but also encourages a healthy gastrointestinal (GI) tract by helping establish a normal population of GI bacteria that digests the food they eat.
Some chinchillas, like some people, are genetically predisposed to dental problems. By taking their pets for regular, annual veterinary check-ups and by being attentive to their animals’ food consumption, stool production, and weight, chinchilla owners can help catch signs of dental disease early before this disease develops into a significant, life-threatening problem.