Dental disease is one of the main reasons pet degus are presented to veterinarians. In a retrospective clinical series of 300 animals, dental problems were found in 60%, rising to 76% among animals older than two years. These figures describe that clinical sample, not all pet degus. Malocclusion is common, but other tooth disorders also occur. Experimental studies show that mineral balance and food structure affect dental health. Suitable hay, fibrous plants and a balanced overall ration support normal chewing and tooth wear.
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The dentition of the Octodon degus
Tooth development
Degus are born with erupted permanent incisors in functional occlusion. In the dental eruption study, premolars appeared on days 2â3 and first molars on days 4â5; these first cheek teeth began functioning together around days 9â11. Pups were observed sampling solid food from approximately day 8. Second molars erupted around days 17â20 and third molars later, with complete functional occlusion observed by day 72. These are different stages and should not be collapsed into a single eruption or weaning date. The authors recommended delaying weaning until at least six weeks. The clinically visible dentition is permanent. The possibility of transient prenatal deciduous tooth structures is distinct from a postnatal change from milk teeth to adult teeth.
Anatomy
Degu teeth are continuously growing and erupting, or hypselodont, with long crowns and open apices rather than conventional closed roots. The dental formula is I 1/1, C 0/0, P 1/1, M 3/3 on each side, giving 20 teeth: four incisors, four premolars and twelve molars. Chinchillas and guinea pigs share this formula, but it should not be generalised to every hystricomorph rodent.
Degus have two pairs of incisors, which are visible and naturally coloured yellow/orange on the outside. They are separated from the premolars and molars by a large empty cavity, the diastema. The enamel of the incisors is only present on the orange side and on the edges, and their physiology makes these teeth very resistant to wear. The reserve crown lies below the gum line within the alveolus; it is distinct from the exposed clinical crown. The part above the gum line, and therefore visible, is called the clinical crown. Finally, there are the premolars and molars at the back of the mouth, which are used for thorough chewing and, in case of problems, can create malocclusions.
Abrasion and mastication
Because of its natural diet, the Octodon degus eats plants that are relatively low in energy. It therefore needs to eat a large quantity of plants to meet its needs. This involves a long and meticulous chewing process, which allows the teeth to wear well. The incisors and the other teeth play a separate role during meals. To chew properly, the incisors work from top to bottom, while chewing with the premolars and molars is done from left to right. Gnawing and cheek-tooth chewing involve different jaw movements. Both contribute to normal function; their differences do not establish a universal explanation for the frequency of combined incisor and cheek-tooth disease. Rodents of the suborder Hystricomorpha have a specific muscular and articular anatomy in the mandibles, allowing them to chew and gnaw quite powerfully.
Mechanisms of dental disease
Dental disease, and in particular dental malocclusion, is one of the most common conditions in degus. In the retrospective study, dental disease was especially frequent among older patients. It may initially be obscured by other signs, such as breathing difficulty caused by dental elongation into adjacent structures. An unsuitable diet is an important contributor, but trauma, structural abnormalities and other diseases also matter. Caries, periodontal disease and resorptive lesions can be missed without a detailed examination. Elodontomas are proliferations of dental tissue that may obstruct feeding or breathing; they should not be described as the inevitable result of every infection or of repeated rubbing.
Dental diseases are often very painful for the rodent, and can lead to many other health problems, such as the cessation of intestinal transit. In the degu, as in many small mammals, it is essential that the transit remains stable, because the degu eats all day long. But transit is far from being the only thing affected. Sight, hearing and smell can be affected, in various ways, to a greater or lesser degree. This also causes pain and stress, which can lead to other conditions. It is a never-ending cycle, which will lead to chronic pain and stress.
Causes
Diet
In the wild, the degu spends most of its days outdoors, searching for food. Its diet consists mainly of plants (stems, leaves) with seeds contributing seasonally. By chewing these plants, the degu wears out its premolars and molars spontaneously throughout the day. By eating seeds, pods or bark, it also wears out its incisors. Through its diet, but also its exposure to the sun, the degu will produce enough vitamin D, which is essential for the good growth of the teeth.
These two types of chewing are complementary and should be offered in captivity. While the degu has a natural tendency to gnaw in its cage, often out of boredom, it is chewing that is most often the problem. Hay plays a very important role in this, but the degu often refuses to eat sufficient hay. This is often due to the fact that the degu is fed too much food all the time.
Diet is an important modifiable risk factor. This site favours a ration based mainly on fibrous plants, with a limited seed component; its 80% plant/20% seed framework is practical husbandry guidance, not a universal clinical prescription or a fixed wild annual proportion. A calcium-to-phosphorus ratio around 1.6:1 to 2:1 is discussed in this context. The original 1.6:2 ratio was inconsistent with that guidance and should not be used.
Assess the complete ration, including hay and other plants. The suitability of pellets depends on their formulation, amount and the individual animal; all pellets are not nutritionally identical. Food that is too energy-dense may reduce time spent chewing fibrous material, and mixed feeds may allow selective feeding. A lower-energy, fibre-rich ration can also support appropriate body condition. SAB Degu Mixis one approach discussed on this site. Vitamin Dmust be supplied appropriately, but supplementation and any use of UV lighting require assessment of the existing diet and exposure; more is not automatically better.
Other causes
Mazu, a degu with teeth growing through its skull and touching the eyeball, which cannot be operated on.
While diet plays a major role in dental disease, there may be other causes :
- Housing and vitamin D: inadequate vitamin Dstatus can affect mineral metabolism, but lack of direct sunlight alone does not prove deficiency when an appropriate dietary supply is present. Assess diet and any UV exposure with your veterinarian.
- Metabolic bone disease: this is a brittleness of bones and teeth, which is found in many rodents and may exist in the Octodon degus.
- Insufficient or abnormal tooth wear: a ration dominated by readily consumed concentrated food may reduce prolonged chewing of fibrous plants.
- Genetic predisposition: Many other rodents may show genetic predisposition to dental disease in certain lines. These are numerous, and can include malformations of the skull or teeth.
- Traumatic damage: It is possible that by accident, teeth are dislodged or deflected by traumatic damage, which interferes with natural wear. This may be due to bites, falls or simply because the degu gnaws on its bars out of boredom.
- Stress: The Octodon degus is sensitive to loud noises or smells, or being too hot or too cold depending on the environment it is in. These conditions cause psychological and physiological stress. Stress reduces the strength of the periodontal ligaments, which hold the teeth in their sockets. The quality of the ligaments and gums is also affected, with injuries occurring more easily in stressed individuals.
Symptoms
X-ray of the skull of an Octodon degus with dental malocclusion – Photo by Isabelle Wornham
Symptoms of dental problems in the degu can go unnoticed quite easily. Indeed, it is possible that the degu presents a small weight loss over a long period, or presents symptoms which lead to other tracks, in particular respiratory. It is therefore essential to monitor the condition of the degu in order to detect dental problems early.
Among the most common symptoms, we find :
- Weight loss: One of the first symptoms of many health problems is weight loss, which is quite pronounced and long lasting. It is recommended that these degus be weighed on a weekly basis, so that their weight curve can be monitored.
- Excessive growth of the incisors: if the growth of the incisors is in itself a dental pathology, it can result from other health problems, not allowing the degu to wear the teeth correctly. Teeth may be too long, of different sizes or growing crooked.
- Swelling around or under the jaw: this may be a sign of a dental problem. Possible causes include dental elongation, an abscess or a proliferative lesion; examination is needed to distinguish them.
- Difficulty with chewing: If the degu has a lot of difficulty chewing, or “chokes” during feeding, it is possible that something is bothering its teeth.
- Drooling/hypersalivation: an animal that starts drooling may have dental problems, but also many other health problems.
- Feeding difficulties: the degu may have many feeding difficulties, and may stand near food, or pick it up and drop it.
- Nasal / eye discharge: a degu that “cries” may be the result of an infection or dental disease affecting adjacent bone or soft tissues.
- Difficulty breathing: it is possible that too much tooth growth is preventing the animal from breathing properly, or is causing discomfort, which can lead to lung infections.
- Dirty or unkempt coat: this may be a sign of pain or difficulty in using the tongue to properly maintain the coat.
- Stopped transit: whether complete or partial, stopped transit may be related to problems.
- White or pale yellow teeth: white teeth in degu are a sign of dental imbalance and may also be related to other conditions.
Diagnosis
Whenever a dental problem is suspected, the degu should be taken to a competent veterinarian for diagnosis.In order to do this, it will often be necessary to carry out one or more clinical examinations. First, the condition of the incisors can be checked and the skull palpated for any suspicious mass. It is necessary for the veterinarian to carry out a complete imaging of the head, in order to avoid missing early conditions.
One of the most common ways of detecting malocclusions is by X-ray. The animal is anaesthetised and x-rays of the skull are taken from different angles to check the growth of premolars and molars. Computed tomography is also a good way to detect any problems, especially for molar crowns. However, it is also worthwhile for the veterinarian to carry out an intraoral examination, so that other lesions, such as periodontal disease, caries or dental resorption, are not missed. It is possible to perform these examinations via endoscopy, in order to be able to detect these dental disorders, which are not always visible by radiography. Finally, a “manual” examination must also be carried out by the veterinarian, through observation and palpation of the degu’s skull, in order to detect possible conditions and to check the state of the incisors and the mouth.
Treatments
There are several methods to treat your degu. They almost all require a veterinary procedure, under general anaesthesia. According to the diagnosis, the veterinarian will have to treat the degu in the most appropriate way. It is possible to simply file the teeth in the simplest cases of malocclusions, but also to remove cancerous masses… Only a veterinarian is able to make the diagnosis and choose the appropriate treatment. In addition to the procedure under anaesthesia, the veterinarian may provide antibiotic treatment, analgesia or nutritional support. Some dental conditions can be resolved, while others need repeated treatment and long-term dietary management. Regular reassessment is needed because recurrence and prognosis depend on the underlying lesion.
Dental diseases and disorders in Octodon degus
Incisor disorders
Incisor disorderss in degus (Vladimir Jekl).
(A) Enamel elongation and depigmentation of clinical crowns.
(B) Severe malocclusion and deviation of the right mandibular incisor after traumatic injury.
(C) Iatrogenic right lateral deviation of the mandibular incisor and overall coronal lengthening after trimming of clinical crowns with forceps.
(D) Incisor displacement and malocclusion secondary to maxillary melanoma.
Malocclusion
Malocclusion of the incisors is the excessive growth of the incisors, or irregular growth, which no longer allows natural wear movement.
It is the easiest dental malocclusion to understand because it is directly visible. This pathology comes from the elongation of the incisors, or an irregular, “twisted” growth of the latter. Incisor-related diseases and especially coronal elongation can be related to poor nutrition and malocclusion of molars and premolars in the mouth.
Other conditions
The degu can also develop other incisor conditions than malocclusion. Indeed, it is possible to encounter conditions such as depigmentation, enamel hypoplasia (the degu has white teeth), ridges on the enamel, or demineralisation of the cementum or dentine. These conditions are due to disorders of tooth-forming tissues, linked to metabolic imbalances. The latter are often due to a poor diet, systemic diseases or trauma (accidents, bites, ….). It is therefore important to regularly check the condition of your degu’s incisors.
A marked change in incisor colour warrants assessment; nutrition is one possible factor, but colour alone does not diagnose the cause. In general, the degu should have orange teeth, the significance of pale or yellow areas depends on age, the tooth surface and other findings. If the degu has had white teeth for some time, it is very important to check the overall condition of the jaw to avoid missing another related dental condition.
Premolar or molar disorders
CT images of the sagittal plane of the reconstructed maxillary dental arch in 3 D model, mediolateral medial view (A), and surface reconstruction (B).The apical elongation and reserve crown of the fourth premolar erupted into the nasal cavity (A), with a bulging apex in the nasal bone (B). Irregular structure suggesting dysplastic changes in tooth structure. The reconstructed images are visualised using Drishti volume rendering software. (Vladimir Jekl and Tomas Zikmund).
Malocclusion
Dental malocclusions of the premolars or molars are the excessive growth of these teeth, which may result in the choking of the animal or the perforation of jaw bones.
Dental malocclusions, particularly those affecting premolars and molars, are very common in rodents, and are most common in the Octodon degus. In chinchillas, malocclusions appear to be related to nutritional and genetic causes, which are the dominant factors in dental disorders. In captivity, degus tend to have longer teeth than in the wild. This is related to reduced chewing, especially due to the unsuitable and less abrasive industrial food. In an experimental study, a high-phosphorus dietary treatment with a calcium-to-phosphorus ratio around 1:1 was associated with dental changes over six months; this does not predict the same outcome in every animal or with every diet sharing that ratio.In addition, it also reduces the bone density in some parts of their body. It is the excessive growth of premolars and molars that causes most of the clinical signs associated with dental disease in degus. The elongation of these teeth can lead to pain in particular, due to the pressure of the teeth on the nerve endings. In addition, it is possible for the tooth to grow through tissue and damage the oral area, or puncture bony areas, such as the nasal or frontal bone.. It is then possible to feel irregularities during palpation of the external areas of the jaw.
Lateral skull radiograph of a degu who presented with dyspnoea. The radiographs show severe coronal elongation and apical deformities of the premolars/molars with the formation of a clinical crown tip of a mandibular premolar (arrow). The diseased apices of all cheek teeth are clearly visible (red lines). The apical radiographic abnormality of a maxillary premolar indicates a dysplastic change (pseudodontoma, blue). Histopathological examination confirmed the presence of a pseudodontoma of the premolar and an elodontoma in the nasal cavity. (Vladimir Jekl)
Other diseases
With impaired chewing, the degu may have swallowing problems or develop pronounced dysphagia. The crowns of the molars also tend to elongate in the degu, often towards the tongue. It is then possible for the teeth to “jam” the tongue in severe cases, with the formation of a dental “bridge”.
Periodontal disease
Periodontal disease attacks and destroys the tissues that support the teeth, such as the gums and bones. It is a bacterial disease that develops slowly, sometimes over several years.
Little studied in the degu, it is a very common disease in the chinchilla, which is a closely related species. It is therefore possible that this disease, reported in 63% of chinchillas in the cited clinical sample, is also present in the degu. This disease is related to various factors such as: other dental pathology, genetic factors, age, oral microflora and nutrition. Untreated periodontal disease will progress and lead to bone and tooth resorption.
Dental resorption
Dental resorption is the progressive disappearance, physiological or pathological, of the crown and/or root of a tooth.
In the degu, this leads to the loss of the clinical crowns of the premolars and molars. This greatly impairs chewing and feeding. The loss of the tooth creates a void where food remains can lodge, thus creating other conditions (caries, periodontal disease). Tooth resorption can also create a malocclusion due to the lack of wear of the opposing tooth. This condition is a source of chronic intraoral pain, leading to reduced and insufficient food intake followed by weight loss and potential metabolic complications such as metabolic disturbances, including ketosis or ketoacidosis in appropriate clinical circumstances and hepatic lipidosis (excessive fat accumulation in the liver). Therefore, patients with clinical signs and symptoms suggestive of periodontal disease should be assessed and treated appropriately.
Dental caries
Dental caries is the demineralisation and destruction of the tooth after a bacterial infection. This occurs through the production of lactic acid by cariogenic bacteria. Dental caries has been documented in chinchillas and can also occur in degus. A figure from one species or clinical sample must not be presented as the prevalence in all captive rodents. Again, the diet is to blame. High sucrose levels, as well as a lack of long chewing, lead to the formation of cavities. Indeed, poor chewing can lead to increased plaque formation on the teeth and reduced salivation. In addition, dental malocclusions of molars and premolars also lead to the accumulation of bacterial plaque, which is linked to caries.
Premolar and molar disorders in degus.
(A) Coronal elongation with spur formation of the right mandibular first cheek tooth.
(B) Bilateral coronal elongation of the mandibular first premolar tooth, with typical mandibular spur formation, “bridge” and subsequent tongue entrapment. (Vladimir Jekl)
NĂŠoplasie et lĂŠsions cancĂŠreuses
The most common oral tumours in degus are elodontomas. They are defined as a continuously developing hamartoma of odontogenic tissue and alveolar bone at the periapical bud of elodont teeth. In simple terms, a large mass of tissue that develops in the area of the skull. These lesions are related to trauma, inflammation, age or other dental diseases, especially malocclusions. Prognosis varies with the lesionâs location and extent, breathing and feeding ability, and available treatment. A universal six-month survival estimate is not established by a single case report. Palliative care and assisted feeding may form part of an individual plan when appropriate.
Other tumours found in the oral cavity of degus include melanoma and fibrosarcoma. Finally, the degu may develop “pseudodontomas”, (pseudoneoplastic lesions) as a result of the continuous deposition of dental structures, creating a mass. Unfortunately, this mass can obstruct the nasal cavity, causing intermittent or chronic mild to severe respiratory distress..
Lt 10 V – Rt D lateral oblique radiographs of the skull of a degu with incisor malocclusion (mandibular incisors highlighted in yellow), apical elongation of mandibular incisors and premolars and molars (apices highlighted in red). In this case, the respiratory problems were associated with a dense radio mass corresponding to an elodontoma (blue), which obstructed the nasal cavity. (Vladimir Jekl)
Dental abscesses
Abscesses are lumps of pus in a body cavity. In degus, these can be related to primary (bacterial) or secondary infections. The latter can have several causes, such as trauma (bites, splinters, …) or other dental diseases. They can develop around the teeth and in the soft tissues for the most important ones. It is not uncommon for dental abscesses to be related to malocclusions. In this case, it is necessary to differentiate between if they form at the base of the tooth and are then related to the penetration of the root in tissues or if they form in the soft tissues, due to an elongation of the dental crowns. These different abscesses need to be managed appropriately in order to treat the degu correctly.
Conclusion
A suitable high-fibre diet, appropriate mineral balance, safe opportunities for chewing, a good social and physical environment and regular monitoring reduce avoidable dental risks. This siteâs approximate 80% plant/20% seed framework and calcium-to-phosphorus guidance around 1.6:1 to 2:1 are not individual prescriptions or guarantees against disease. Vitamin Dneeds must be met safely through an assessed overall plan. If appetite, weight, chewing or breathing changes, seek veterinary advice promptly rather than attempting to file teeth or change supplements at home.
Sources
Jekl, V., Hauptman, K., Knotek, Z. (2011). Diseases in pet degus: a retrospective study in 300 animals. J Small Anim Pract, 52(2), 107-112. https://doi.org/10.1111/j.1748-5827.2010.01028.x
Jekl, V., et al. (2011). Impact of pelleted diets with different mineral compositions on the crown size of mandibular cheek teeth and mandibular relative density in degus (Octodon degus). Vet Rec, 168(24), 641. https://doi.org/10.1136/vr.d2012
Gumpenberger, M., et al. (2012). Impact of a high-phosphorus diet on the sonographic and CT appearance of kidneys in degus, and possible concurrence with dental problems. Vet Rec, 170(6), 153. https://doi.org/10.1136/vr.100257
Mans, C. & Jekl, V. (2016). Anatomy and Disorders of the Oral Cavity of Chinchillas and Degus. Vet Clin North Am Exot Anim Pract, 19(3), 843-869. https://doi.org/10.1016/j.cvex.2016.04.007
Reynolds, T. J. & Wright, J. W. (1979). Early postnatal physical and behavioural development of degus (Octodon degus). Laboratory Animals, 13(2), 93-100. https://doi.org/10.1258/002367779780943576
Jekl, V., et al. (2011). Dental Eruption Chronology in Degus (
Octodon Degus
). Journal of Veterinary Dentistry, 28(1), 16-20. https://doi.org/10.1177/089875641102800103
Jekl, V., et al. (2008). Elodontoma in a Degu (Octodon degus). Journal of Exotic Pet Medicine, 17(3), 216-220. https://doi.org/10.1053/j.jepm.2008.04.001
Skylark Vets (2025). Dentistry in guinea-pigs, degus and chinchillas. Veterinary patient information. https://www.skylarkvets.co.uk/index.php/2025/02/12/dentistry-in-guinea-pigs-degus-and-chinchillas/
Meserve, P. L., Martin, R. E. & Jaime, R. M. (1983). Feeding Ecology of Two Chilean Caviomorphs in a Central Mediterranean Savanna. Journal of Mammalogy, 64(2), 322-325. https://doi.org/10.2307/1380568
Edwards, M. S. (2009). Nutrition and Behavior of Degus (Octodon degus). Veterinary Clinics of North America: Exotic Animal Practice, 12(2), 237-253. https://doi.org/10.1016/j.cvex.2009.01.003
Quesenberry, K. E., et al. (Eds.) (2021). Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery (4th ed.). Elsevier/Saunders. https://evolve.elsevier.com/cs/product/9780323484350?role=faculty
Jekl, V., Zikmund, T. & Hauptman, K. (2016). Dyspnea in a Degu (Octodon degu) Associated with Maxillary Cheek Teeth Elongation. Journal of Exotic Pet Medicine, 25(2), 128-132. https://doi.org/10.1053/j.jepm.2016.03.003
Crossley, D. A. (2001). Dental disease in chinchillas in the UK. Journal of Small Animal Practice, 42(1), 12-19. https://doi.org/10.1111/j.1748-5827.2001.tb01977.x
Crossley, D. A., Dubielzig, R. R. & Benson, K. G. (1997). Caries and odontoclastic resorptive lesions in a chinchilla (
Chinchilla lanigera
). Veterinary Record, 141(13), 337-339. https://doi.org/10.1136/vr.141.13.337
Boy, S. C. & Steenkamp, G. (2006). Odontoma-like Tumours of Squirrel Elodont IncisorsâElodontomas. Journal of Comparative Pathology, 135(1), 56-61. https://doi.org/10.1016/j.jcpa.2006.03.002
HarcourtâBrown, F. (1997). Diagnosis, treatment and prognosis of dental disease in pet rabbits. In Practice, 19(8), 407-427. https://doi.org/10.1136/inpract.19.8.407