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February 19, 2020

Dental Disease in Small Mammals

by Dianne Cook, LVT

February is National Pet Dental Health Month! Veterinarians across the country frequently celebrate by providing discounted dental cleanings for dogs and cats, but what about our small herbivore and rodent companions? Is dental health as important for our exotic companion mammal friends? Absolutely, but in different ways! As animals with constantly growing teeth, dental disease is one of the most common health-related reasons small mammals are taken to their veterinarian every year. Though the cause varies, dental disease can result in substantial, and even life-threatening, health concerns in small pets, so it is essential to learn as much as possible about prevention and early detection.

Normal Tooth Anatomy

Because many exotic companion mammals were designed to eat diets comprised of thick, coarse vegetation, they evolved hypsodont teeth. These long-crowned teeth lack an anatomical root, and continuously grow throughout the animal’s life, making up for the substantial wear and tear resulting from a lifetime of chewing on abrasive materials. If their teeth become overgrown it can result in uneven wear, malocclusions (the teeth not lining up properly) or other uncomfortable abnormalities, which can ultimately affect your pet’s ability to feed themselves.

Rodents and small herbivores have easily visible incisors - the long, chisel-like teeth at the front of their mouths (two upper and two lower). Many small mammal pet parents are surprised to learn their pets’ tiny mouths are also hiding numerous cheek teeth. Believe it or not, rabbits have a total of 28 teeth (including two small teeth right behind their upper incisors called “peg teeth”), guinea pigs and chinchillas boast 20 teeth, and hamsters, gerbils, rats, and mice all have 16 teeth! Interestingly, small herbivores like rabbits, guinea pigs, and chinchillas have a mouth full of open rooted teeth. Though small omnivorous rodents like rats, mice, hamsters, and gerbils also have perpetually growing incisors, their cheek teeth do not continue to grow, as rabbits and other small herbivores do. Regardless of species, that’s a lot of teeth to keep an eye on, especially when you can’t easily visualize the majority of them at home. This is what makes it so important for pet parents to monitor for any signs of dental concerns, and to ensure routine dental care by a trusted veterinarian.

Causes of Dental Disease

Any physical or anatomic anomaly that interferes with the eruption and/or wear of your pet’s teeth can lead to dental disease. The causes of dental disease are lumped into two categories: congenital and acquired. Congenital dental disease is the result of an issue present from birth, whereas acquired dental disease is a result of external factors, meaning it has not been inherited. Since the dental issues are present from birth, congenital dental disease is often detected when the animal is much younger. Acquired dental disease, on the other hand, is far more common than congenital dental disease, and most often results in subtle changes over time; therefore, most animals are diagnosed when they are older. Though no dental disease is good, acquired dental disease is most often preventable, so proactive pet parents have a chance to prevent this serious health concern, eliminating it from ever becoming an issue in the first place.

Diet and Husbandry

What may come as a surprise to some pet parents is the substantial impact appropriate diet and husbandry has on the dental health of small mammals. Improper diet and husbandry are arguably the most common cause of acquired dental disease seen in our exotic companion friends. For small herbivores, a diet lacking in a diversity of free choice grass-hays is the single most common cause of acquired dental disease and can quickly result in improper wear of the teeth, causing painful sharp points, overgrowth, and even potentially abscessed teeth. Though more and more pet parents are learning how important hay truly is to their small herbivore’s overall well-being, some pet parents still feed diets consisting predominantly of a commercially manufactured food, considering hay as more of a treat or snack. Though a high-quality, uniform, fortified pelleted diet is an essential way to provide your little one with the daily macro- and micro-nutrients they need, a combination of free-choice grass hay varieties should make up the overwhelming majority of your small herbivore’s diet. Beyond appropriate food choices, small herbivores should be provided with plenty of opportunities to interact and play with species-appropriate chews made from all-natural materials. Though these chews will only work to keep your herbivore’s incisors worn down, they will also provide a substantial amount of physical and mental enrichment.

Small omnivores should also be provided with a uniform, high-quality, fortified diet, but it is essential they are also offered a variety of supplementary foods rich in fresh greens, vegetables, and species-appropriate proteins. These fresh foods will not only provide your little one with substantial mental and nutritional enrichment, but their coarse consistency will help keep those constantly erupting incisors worn down. Small omnivores should also have access to species-appropriate chews fashioned from materials such as dried sticks and cardboard. It is important to make sure you are always providing chew items that are nutritionally appropriate and have been grown/made without the use of chemicals.

Regardless of species, a diet lacking in calcium and other essential micro-nutrients can also result in weak, especially fragile teeth. Though broken hypsodont teeth will generally grow back, any missing/damaged teeth can result in a malocclusion, which can result in tooth overgrowth and lead to self-feeding difficulties for your little one.

Trauma and Disease

Any injury to the face or head, regardless of how minor it may seem, can result in abnormal dental growth and acquired dental concerns. Serious traumatic injuries, such as a broken jaw, can result in misalignment of the teeth if the jaw heals in an abnormal position. Less severe injuries like a chipped tooth can disrupt the apex (the portion of the tooth below the gum line) which can affect the rate and direction of tooth regrowth. Tooth breakage can happen naturally because of especially hard food items, but can also be the result of cage chewing, falling or being dropped, or even fighting with a cage mate. Though open rooted teeth grow quickly, it can take several days to weeks for teeth to grow back, depending on how far back the tooth was broken to begin with. During this time of regrowth, changes in occlusion (how the teeth meet) may result in improper alignment, meaning your pet’s other teeth run the risk of becoming overgrown. As a pet parent, it is essential to monitor this regrowth and communicate with your veterinarian if anything seems abnormal.

As prey species, small mammals are incredibly efficient at hiding health concerns. Sometimes the first indication of a severe underlying systemic disease is minor-to-moderate dental disease. As discussed earlier, appropriate calcium levels are essential to promote healthy teeth, but beyond diet, some diseases can deplete calcium levels within the body, resulting in weaker teeth and bones. If the jawbone softens around the base of the teeth, the teeth can shift positions, resulting in malocclusions. Any health concern that affects your pet’s desire or ability to eat appropriate types and volumes of foods can also affect your pet’s teeth. As we’ve discussed, open rooted teeth are designed to be ground down by a consistent intake of course, fibrous vegetation. If a sickly small mammal isn’t eating as much as they should, or if self-feeding ceases altogether, their teeth will have nothing to wear against and therefore run the risk of overgrowth.

Localized infections, such as tooth root abscesses, are also quite common causes of acquired dental disease in exotic species. Dental infections are most commonly arise when the apex of the tooth becomes overgrown, leading to instability in the tooth, inviting inflammation and infection to set in under the gingiva.

Genetics

Congenital dental disease is any dental issue that is a direct result of an issue that was inherited by your pet and was present at birth. Throughout years of selective breeding for certain physical traits, humans have altered the anatomical structure of many breeds of small mammals. Sometimes, these selective breeding programs have resulted in changes in skull shape, which can have a significant impact on how the teeth connect and wear on each other. Inbreeding or genetic mutations can also result in jaw structure abnormalities affecting the length of the jaw itself, or how well the mandible (lower jaw) and maxilla (upper jaw) align. It is important to remember that congenital dental disease is a chronic health concern and will require frequent visits to an exotics friendly veterinarian for life-long maintenance. With proper care, however, small mammals suffering from hereditary dental issues can live long, happy lives.

What To Watch For

As species hardwired to disguise signs of sickness, weakness, or pain, the early signs of dental disease are often quite subtle. Therefore, routine physical and dental exams by a trusted veterinarian are incredibly important for all small mammal friends. If dental problems are not caught early, they will continue to worsen and if no intervention is made, they will inevitably result in a painful condition that even the most stoic of small mammals won’t be able to conceal and sadly, may not be able to overcome. If your small friend exhibits any of the following signs, it’s important you reach out to your veterinarian immediately.

Changes in Eating or Appetite

One of the most recognizable signs something is wrong with your little one is when they suddenly stop showing interest in the food they once loved. Sometimes, the first sign of dental disease is a sudden shift to being more selective about their food choices. If you notice that your pet has stopped eating coarser items such as pellets, veggies, and hay, but will still eat softer foods such as fruits or soft leafy greens, they may be trying to tell you their mouth hurts. Dental disease often results in sharp points along the edge of the teeth. These jagged edges can cause painful ulcerations along the cheek and/or tongue, making chewing painful. If the dental disease progresses to the point of substantial overgrowth, you may also notice your small friend trying to pick food up, only to have it fall out of their mouth as they attempt to chew. If your pet becomes physically incapable of eating, they may stop trying altogether which is always an urgent situation.

Physical Changes

Dental disease can also lead to watery eyes, nasal discharge, and drooling. A large percentage of the overall tooth structure is located beneath the gum line and is also adjacent to the sinuses and tear ducts. Any infection or inflammation of the teeth can result in partially or totally blocked tear ducts, or irritation to delicate mucous membranes causing nasal drainage. Excessive salivation is most often a result of pain or the inability to completely close the mouth due to overgrown teeth. If your furry friend’s eye(s) start to bulge, or if your pet’s face appears swollen or lopsided, it may be a sign of a tooth root abscess. It is important to visit with your veterinarian as soon as any of these changes are noted.

Prevention and Early Detection

The best treatment for dental disease is prevention. Though some circumstances are out of our control, providing your pet with optimal care is the best possible way to avoid the serious consequences of uncontrolled dental disease. Though congenital problems are regrettably unavoidable, many forms of acquired dental disease are preventable. First and foremost, it is essential to provide your furry family members with a high-quality diet that is nutritionally appropriate for their species. Ensure small herbivores are provided a diet consisting of unlimited access to grass hay varieties and a measured volume of uniform, fortified pellets. It is also important they have daily access to a healthy assortment of dark, leafy greens and plenty of enriching chew toys to play with. Small omnivores should be provided with a high-quality, uniform fortified diet, along with species-appropriate supplementary foods and access to plenty of natural chews.

Though it is difficult to visualize our small pet’s cheek teeth, it is important for pet parents to familiarize themselves with the normal appearance of their pet’s incisors. If any changes in color or shape are noted, or if the incisors appear excessively long, report these changes to your veterinarian as quickly as possible. Since examining the incisors alone is not enough to ensure complete dental health, it is important to seek routine veterinary care at least once a year. Part of a complete and thorough physical examination includes a dental exam, during which your veterinarian may use specialized tools to visualize your small pet’s premolars and molars. Dental examinations may even include low-grade sedation or anesthesia, or even the potential of dental radiographs, to truly evaluate all teeth.

As pet parents, we all do our very best to make sure our pets live the healthiest, highest quality life possible. Though some causes of dental disease are outside of our control, ensuring your little one is fed a high-quality diet and receives routine veterinary care are easy ways to keep your small friend’s choppers nice and healthy throughout their entire lives. Even if sudden trauma or hereditary misfortune means your pet develops dental disease, frequent veterinary care for routine maintenance can help keep your little one happily munching for years to come. 

Learn More

How to Select Hay Your Rabbit or Guinea Pig Will Love

What Are the Best Vegetables and Leafy Greens for Guinea Pigs?

How to Tell If Your Rabbit is Sick

All About Chewing