Rabbit and Large Herbivorous Rodent Dental Disease

severe incisor malocclusion Keller labeled

Abstract

Dental malocclusion is a common diagnosis in rabbits, guinea pigs and chinchillas and management requires a strong understanding of the normal anatomy and physiology of elodont dentition. Both congenital and acquired dental disease occur when there is a mismatch of dental growth and attrition, particularly when this is paired with malocclusion. The diagnosis of dental disease should be pursued when there are a supporting history, presenting complaint or general physical examination findings. A focused five-part oral examination that screens for apical and intraoral overgrowth can facilitate the identification of individuals suffering from dental disease, even if direct premolar and molar observation is not performed. Skull radiographs allow evaluation of apical tooth overgrowth and comorbidities including sinus and middle ear disease however when available, computed tomography can add a remarkable amount of information to the clinical case management in comparison to radiographs. Definitive or palliative therapy for dental diseases is rarely an emergency, and animals should be stabilized prior to any procedures with fluid replacement, analgesia, and nutritional support. Based upon the specific diagnosis, an occlusal adjustment, extractions, apicoectomies or therapy for abscess may be performed. Specialized equipment for the specific elodont dentition are available and should be utilized in these cases.

Outline

chin skull rad Keller               dental arcade Keller
  • Anatomy
    • Tooth type: elodont hypsodont
    • Dental formulas
    • Occlusion and occlusion angles
    • Dynamic temporomandibular joint
  • Pathogenesis of dental disease
    • Factors affecting dental attrition and growth
    • Congenital vs acquired malocclusions
  • Treatment
    • Stabilization
    • Coronal height reduction
    • Extractions
    • Options for odontogenic abscesses

About the presenter

Krista Keller is an Assistant Professor at the University of Illinois at Urbana-Champaign. Dr. Keller is also an avian and exotics telemedicine specialist for Abaxis, Incorporated. Krista earned a Doctorate of Veterinary Medicine (DVM) from Ross University School of Veterinary Medicine in 2010.  She then completed an internship in companion animal medicine and surgery at Louisiana State University and a residency in zoological companion animal medicine at the University of California at Davis… [Learn more].

 

Dental charts

Download the chinchilla, guinea pig, and rabbit dental records, generously shared by Dr. Keller.

Chinchilla Guinea pig Rabbit
chin dental chart screenshot

 

Also download the Rabbit, Guinea Pig, Chinchilla Husbandry Questionnaire shared by Dr. Keller. Additional small mammal history forms are available for download in Forms & Questionnaires.

UI husbandry question

 

Webinar recording

 

Post-test

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Expert Q+A

Although Dr. Keller was able to answer many questions during the live event, a large number of remaining questions were generously answered by email and are posted below:

 

GENERAL

What dental textbooks for exotic dentistry do you recommend as most useful?

I would recommend the newest edition of Ferrets, Rabbits and Rodents for novices wanting to do more dentistry. There is a pretty good chapter to get you started, and also lots of additional information on other diseases, diagnostics, treatments, since most of our patients like to have more than one diagnosis.  However, for me the best descriptions of the pathogenesis and clinical course of dental disease is inThe Textbook of Rabbit Medicine.  

 

ANATOMY/PHYSIOLOGY

How does the periodontal ligament anatomy work in teeth that continuously grow?

Great question! Unfortunately, it is not something that is discussed much in the literature. On radiographs and computed tomography you can definitely see the space where the periodontal ligament [widens] as dental disease progresses, however, I’m not sure histologically/physiologically how it is different… But now I want to ask my dentist friends!

 

PATHOGENESIS/DISEASE SYNDROMES

I’m trying to understand why the tooth grows up or down into the mandible or maxilla but looks normal in the mouth?  Also, if the teeth continuously grow, once you remove one – does it grow back?

The hypselodont dentition moves to the path of least resistance, sometimes that is intraoral and sometimes it is coronal… Most of the time it is both!

As for growing back after extraction. If the tooth is fully extracted, including the removal of the germinal bud then it will not grow back. However, if the crown is inadvertently fractured during extraction, it will grow back (unless the germinal tissue is dead).

Is there a known cause for mandibular abscesses?

Odontogenic abscesses should be considered as an end stage in the spectrum of dental disease as described and not considered a disease state on their own. If teeth are maloccluded, particularly if they are crowded, there are additional pathologic pressures placed on the teeth that cause strain and ability for foodstuff and microbes to move down into the space between tooth and bone.

When you have a mandibular abscess like the one described in the fourth case and find ‘’dead’’ teeth falling out easily, do you find that these teeth will often grow again?

I guess the one good thing about those dead teeth is that they will not regrow!

 

Most of the patients I have here in Brazil with dental disease are guinea pigs. In some cases, after the occlusal adjustment, the patients do not eat by themselves anymore, and that brings all the problems back again. That leads to a very bad prognosis. What can I do to help these patients?

Yes, guinea pig cases can be especially challenging, and I agree they do have a poor prognosis. In general, guinea pigs that have premolar and molar elongation are at heightened risk for temporomandibular joint (TMJ) luxation or subluxation. After this happens, even when you trim the teeth, they have reduced or absent ability to move their jaw correctly, leading to very frequent overgrowth conditions. Some ways to pick up on these cases are: 

      • Palpate over the TMJ to see if you can elicit pain 
      • Perform rostrocaudal (skyline) view of skull to evaluate the TMJ, although if the luxation is dynamic, you may get false negative findings. 
      • After each procedure, attempt to get the guinea pig moving their mouth, this should be elicited once awake by placing a cotton tipped applicator in the oral cavity.   

For those guinea pigs that do have TMJ disease, there are lots of reports of guinea pigs doing better if they are provided with a “chin sling”. Visit  https://www.guinealynx.info/chinsling.html.

Guinea pigs with several mobile teeth:  Is prognosis always terrible?

Mobile teeth should be removed, as they are minimally (or non-) functional.  

 

How often do you see tilted head (vestibular secondary disease) when the patient has a one-sided abscess, etc. causing unilateral bulla pathologies?

Often, but not always. I think lops tend to have awful middle ear disease (according to me they all have infected bullaes until imaging proves otherwise) but don’t always exhibit OVERT vestibular syndrome. Many times they will present for GI stasis or “getting old” but if you look closely (positional nystagmus), then you will identify them!

How often do you see odontomas in your exotics?

I have only ever seen a case of the classic presentation of elodontoma (respiratory distress) and it wasn’t even my case! However, I have diagnosed several patients with elodontomas of different teeth. Overall, the finding is rare. I wonder if we should now be calling this tumor a “hyselodontoma”?

Have you ever seen lower incisors one tooth is white and one tooth is yellow?

I’m not sure what species this is in regard to, but this would be an abnormal finding to have two different colored incisors. Based upon the species, you would have to know which one.

 

DIAGNOSTICS

Is it abnormal to find ingesta in the mouth obscuring the premolars or molars if the rabbit, for example, hasn’t had food for over an hour?

Guinea pigs are the only species that should have food in their oral cavity (well, hamsters with their cheek pouches may be in this category as well!). Rabbits and chinchillas should NOT have food in their mouth unless you are catching them in the act of eating!

When you see abnormal incisors during a wellness exam in a guinea pig that is doing well, do you recommend additional diagnostics right away or wait for any signs to develop? Could diet adjustments alone correct a mild malocclusion?

If I saw abnormal incisors on wellness and the patient was eating hay as the largest part of their diet (as they should), especially if that had developed [malocclusion] (wasn’t there last year) I would pursue it. The development of clinical signs in our species is poorly sensitive for disease due to the whole “I’m prey and I’m gonna be stoic” and some animals may not make it out of a GI stasis episode (because let’s be honest, they always seem to happen over the weekend!!).  

Were there any specific clinical signs in the patient with bullae abscess that made you suspect? Or it was an incidental finding?

Typical signs associated with bullae disease are vestibular in nature and may also include facial nerve paralysis, however, I am always suspicious of rabbits with a chronic course of GI stasis, or GI stasis when there are no other physical examination findings or historical reasons to suggest why. My secret physical examination finding to uncovering these sneaky cases is to not only evaluate for resting nystagmus, but also to evaluate for positional nystagmus! It has saved me many times. I don’t really remember the case that I showed you the CT of (sorry), but many times, rabbits (particularly lops for some reason) can have pretty remarkable bullae lesions and yet minimal clinical signs.

 

Do you also do oblique radiographs? If so, how do you do them and how do you interpret them?

I do not perform oblique rads (never have)! They are touted as being able to help you determine if there is mandibular premolar/molar apical abnormalities. The great thing about the five parts of the oral exam is that YOU CAN DIAGNOSE THAT WITH YOUR HANDS! And don’t need radiographs.

Is radiographic increased opacity of the entire cheek tooth arcade of clinical significance?

As dental disease progresses, each tooth goes through some degree of degeneration. In rabbits, this is well described (with radiographic images) in the Textbook of Rabbit Medicine. The classic changes are sclerosis (not sure if this is the right term for tooth?) and loss of the normal striations. So yes! This is clinically relevant change to premolars and molars.

In a follow-up to this reply. Another question was asked:   I have seen the changes described as cementosis.   Is this correct terminology?

…The textbook of Rabbit medicine does not call this cementosis, and I was only minimally aware of this term, so did a little research. The best representation (I think) of cementosis, was in this article: Palaeopathology mini-series: Periodontitis, hypercementosis, and enamel hypoplasia in extinct rhinoceroses.
There is a radiographic figure embedded in this manuscript of rabbit dentition showing (with arrows) some cementosis lesions. What is interesting is that the lesion appears to spread beyond the margins of the dentition.

[Figure 7.8. Progression of acquired dental disease in the Textbook of Rabbit Medicine] …is the best representation of radiographic progression…of dental malocclusion. They call out in figure B how the tooth structure has changed, and that enamel is no longer as wonderfully visible. I have to presume that the changes are secondary to increases in cementin. The textbook does in other areas talk about how there are cementin changes that occur as dental disease progresses… 

When you do rads rather than computed tomography, do you take [a] rostrocaudal view?

I do not routinely take the rostrocaudal view, unless I am looking at sinus pathology or TMJ pathology. Even then, it’s quite tricky to get the right angle and it has rarely changed my course of treatment. Many texts indicate how great this view is for viewing the occlusal angle, which can be true, particularly in guinea pigs. However, when you use the bivalve nasal speculum for the fifth part of the oral exam – you can directly see the occlusal angle!

Are there published measurements or percentages to judge cortical thickness around molar roots?

I think that this question is in regard to interpretation of radiographs, in which case you can only really measure the mandibular cortices. To my knowledge there are no published measurements, however, if you have a normal side, you can always compare to that and you can compare to the cortical thickness of adjacent teeth as well.

 

THERAPEUTICS

Are the sedation protocols you mentioned applicable to rabbits, chins, and guinea pigs, i.e. are the doses all the same?

Yes! The big difference is chinchillas are the crazy ones (there is one in every crowd) that SOMETIMES need a bit higher. And of course, there are individual differences.

Do you typically intubate rabbits for your dental procedures?

I do not intubate all of my patients for their standard occlusal adjustments, but do pursue [endotracheal] intubation for extractions. I would recommend using capnography whenever your patients are intubated.

V-gels are fantastic, however, not appropriate for most dental procedures. They are pretty large in size, taking up most of the oral cavity and making oral visualization and manipulation pretty challenging. 

Is sevoflurane better than isoflurane for these guys [during dentistries]?

I counsel everyone to use what they are comfortable with. I use injectable protocols with isoflurane as a backup. I have rarely used sevoflurane in any of my patients.

What is your monitoring equipment of choice for small exotics (brand and model if possible)?

I love the Cardell Multiparameter touch monitor.

What is your favorite initial analgesic?

I’m not sure that I have a “favorite analgesic”, as I feel as though analgesia is best tailored to the patient’s needs. In cases with acute severe pain, I treat patients with a multimodal protocol that includes a pure mu agonist. In cases with more chronic low-grade pain, I may focus on higher doses of NSAIDs, with some gabapentin. It really depends on the cause and severity of the pain, as well as the species and concomitant diseases of course.

What are your favorite long-term daily analgesics (both for dental disease, and other chronic disease such as arthritis)? I usually use meloxicam + gababentin +/-  buprenorphine:  any thoughts?

Yes, I use a variety of analgesics. I would also think about changing hay to a “softer” hay. At times timothy hay can be a bit fibrous , but meadow can be a bit softer and this is likely more comfortable to chew.

Do you not recommend or use meloxicam as part of anesthetic protocols for Inflammation and pain control? if so, any dose you recommend. if not, how come?

I use meloxicam in patients daily, however, tend to administer it in the post-operative period. Doses are species and route dependent!

Editor’s note: Commonly used doses can be found in the Exotic Animal Formulary.

Are you using methadone in rabbits, or tramadol?

Despite its recent bad press, I like tramadol in rabbits as an analgesic, particularly in multimodal protocols. I have not used methadone, as I tend to use either buprenorphine, fentanyl, or hydromorphone.

Editor’s note: The RACE-approved webinar recording “Sedation & Pain Management of Exotic Companion Mammals” may also prove useful.

What would you use for dental blocks on these species? Do you use bupivicaine like [in] cats/dog?

I have used mental and infraorbital blocks and you can use either lidocaine or bupivacaine.

Editor’s note:  The RACE-approved webinar recording “Sedation & Pain Management of ECM” does touch on locoregional anesthesia, although not specially for dental procedures.

 

When performing crown reductions, do you have to worry about the potential of exposing dental pulp by reducing the crown too much?

Dr. Keller replied:  The only time you really need to be concerned with pulp exposure is if you are trimming teeth (particularly the incisors) to the level of the gumline. In general, all of the root canals of the premolars and molars are below the gumline. This is another reason why the recommendation is not to trim crowns to the lowest height possible, but instead to reduce the crown heights to the most normal occlusion as possible.

So, on these cases where the maxillary apices are above the white line, what should be done to them?

The teeth should be trimmed so that the intraoral crown heights are anatomically correct and the animal should be pushed to eat as much hay as possible.

How are you deciding how much of the incisors to trim in case of malocclusion? I have heard of vets trimming down to the gum line?

When trimming any teeth, the goal should rarely be to be to remove as much tooth as possible. Instead, think about trimming the tooth to put it back into normal occlusion and to give the animal as much function as possible.

Do you use sedation to trim incisors every 10 days? What instruments do you use?

The same equipment [as described in the webinar] and yes, sedation would be very beneficial to your patient. Occasionally I have performed conscious incisor trims on non-sedated animals that are quite sick, to remove a source of pain, but otherwise I am standardly using sedation.

How painful is a conscious incisor trim?

Trimming any of the teeth should not be painful in itself, as the clinical crown does not contain the root canal and system. However, the process has the potential to be extremely stressful and could benefit from an anxiolytic.

Do you have any tips on chinchilla cheek tooth trims? I live in mortal terror of the large vessel at the back of the mandible.

The vessels in the back of the oral cavity are called the retro alveolar vessels. To my knowledge, they are only in rabbits and not in hystricomorph rodents. I have done hundreds upon hundreds of occlusal adjustments in all the species, and I’ve only ever seen it hit once… Keep visualization on the equipment at all times and use small movements, you will be fine.

Have you found any specific shaping/work in the mouth to help with molars that are displaced lingual or buccally – aside from repeat occlusal adjustments?

Unfortunately, some teeth after chronicity have undergone remodeling and they no longer “point” in the right direction. The only options are to get the animal chewing hay AS well as possible to reduce any further changes. But, in those cases, you can also reduce the crown on the lingual and buccal aspect as well as reducing crown height.

 

In patients with severe retrograde tooth elongation, are there any accepted surgical solutions?

Extraction or apicoectomy are really your only options.

Have you ever seen a patient with an abnormal curvature or angle of the incisor, where you were NOT able to use the Crossley luxator properly?

Yep! All the time. After chronic malocclusion it seems that the abnormal pressures placed on the teeth causes them to grow pretty wonky! Those cases are HARD and a good reason to have skull rads PRIOR to doing dental work, because you can have a better idea of what you are getting into. Another option is to do a surgical approach to the incisor through a lateral incision after a surgical flap and then using a drill to remove bone until you can get down to the reserve crown. They aren’t fun, unless you like surgical extractions!

Do you extract the mandibular incisors when the maxillary ones are missing? Or do you leave them in and shorten them on a regular basis?

If it were up to me (and most of my patients) they would rather not see me every few weeks for the rest of their lives. Ideally, if you are removing all maxillary incisors, then the mandibular incisors should and can be extracted as well!

How would you luxate a molar if you don’t have access to a luxator?

Apicoectomy is another option and is what the industry is moving towards. Honestly, a molar luxator is <$50 USD so I would just buy one! I’ve heard of people bending a needle at a right angle to get into the space to luxate the premolar or molar, however, I’ve also had to remove pieces of needle that have broken off between teeth, so it isn’t the best idea!

What are the indications for premolar and molar teeth extraction? And how [can] we avoid or minimize the risk of jaw fractures when doing the procedure (if any indications are considered at all)?

My clinical indications are a tooth that is non-functional or nidus for infection.

Reducing the likelihood of jaw fracture can be done with appropriate technique, using the best tools and if multiple teeth are planning on being removed, considering staging the procedure.

If you remove a molar/premolar, would you need to consider also removing the opposing [ipsilateral] tooth to prevent overgrowth of that?

[Also,] what technique and suture do you use [for extractions]? I find a lot of these break down and form fistulas.

It is according to which tooth I am removing whether I consider removing the opposing tooth. Because the chew cycle of rabbits and hystricomorph rodents is dynamic, the occlusal plane of every tooth is not JUST interacting with the direct opposing tooth, but with additional teeth adjacent to that tooth.  

However, the industry is moving away from intraoral extractions and towards apicoectomies to manage premolars and molars that need to be removed. The early data from these cases indicates that without the germinal bud that is amputated in apicoectomies that the crown that is left behind erupts slowly and leaves behind less of a “pit” and more of a functional occlusal plane.

I do not suture closed [my] premolar-molar extractions unless it is a very rostral tooth being removed and then I create a flap from the sublingual or palatal region to close with small suture. I have also filled in the extraction site with Doxirobe gel (doxycycline hyclate) with great success.

If removing premolars or molars how do you address feeding?  Can they still chew or grind their food?  Is there a limit to how much you can remove?

I have managed rabbits without any premolars and molars live quite well on veterinary prescription diets. And I’ve managed many rabbits that only have one functional side of the mouth do well with normal access to food. Overall, the removal of one or even more premolars or molars does not inhibit normal feeding, and many times removal of a diseased (and potentially painful) tooth causes patients to eat BETTER.

[D]o you put sutures after extraction of tooth?

Closure of premolar/molar extraction sites requires a flap and suturing at some pretty strange angles, thus they are traditionally left open. This is one of the reasons why the industry is moving towards apicoectomies. Incisor extraction sites should be closed.

I recently examined a rabbit found by the owner. It had apparently been housed outside in a wire cage and ate only pellets when he first obtained him. His incisors were not visible above the gingiva, save for 102, which was about 4 mm long. Radiographs showed roots, yet they did not extend to the germinal tissues. Should I plan on extracting these remnants and the peg tooth, or just monitor?

If the animal [has] function and does not have radiographic evidence of infection or draining tracts I would likely leave the tooth remnants in place.

How do you think the various extractions affect quality of life (incisor versus molar, one sided vs. both sided)?

One of my favorite cases was a rabbit that at 12 years of age had had all her teeth extracted. She lived quite happily on a “mush diet” (and a steady diet of blueberries….) Overall, I think animals do well if we can get their disease and pain under control, and if that is with less teeth, then they are ok!

Do you give prophylactic antibiotics after extractions?

Most extractions are secondary to abscessation, and thus, my patients are either on long-term antibiotics or are awaiting a culture result to indicate which antibiotic we will chose for their pet. However, in the less common case of extractions not related to odontogenic abscessation, I would consider a short course of antibiotics.

For marsupialization, does it stay open forever?

The goal of surgery is to keep the site open for as long as possible, however, not forever. Keeping the site open allows for the body to push out and “reject” the capsule of the abscess, thus allowing for long-term control.

 

In cats there is concern for complications using mouth gags due to compromising blood supply from maxillary artery. Is there any potential of this using gags with these exotics? Any length of time using gag that is unsafe?

The mouth gags traditionally used in cats are spring loaded, and thus, place continued pressure to maximally open the oral cavity, thus the association with disease/damage.  

I have trouble keeping the cheek gags in place; [they] easily fall out of the mouth. Any suggestions?

Yes, I do! Place the cheek dilators BEHIND the incisor gag! To do this takes a bit of practice, but you need to only PARTIALLY open the oral cavity with the incisor gag, then place the cheek dilators, then continue to open the oral cavity with the mouth gag. Also, one size does NOT fit all when it comes to cheek dilators! Can always try another size…

How do you keep the mouth open for molar treatment after the incisor [are] removed?

This is a rare situation, however, to keep the mouth open I place the rabbit (it always seems to be a rabbit!) on the tabletop mouth gag and then fashion a sort of behind the head brace to keep their head pulled forward and towards the gag. It’s not pretty, but it can work!

Would you suggest any alternative instruments to rabbit/rodent mouth gags and cheek dilators where they are not available?

Wow, this isn’t something I have thought about for those in other countries I’m presuming? These are specialized instruments that were created for these species, but I’m sure if you really needed to you could “make” something… I hope you can get to ExoticsCon and/or ICARE and get some equipment!

So, you mean you use a normal dog/cat dental machine?

Yes, I use a standard dog/cat dental machine with the water turned off. I have used many different machines dependent on what was available to me. The round diamond burr is used on the slow speed handpiece (premolar and molar crown reduction) and the cylindrical diamond burr on the high speed hand piece (incisor crown reduction).

Is a diamond burr on low speed sufficiently atraumatic?

I’m interpreting this question as asking if the diamond burr is atraumatic to soft tissues? No, the burr can and will cause erosions and or ulcerations and should not come into contact (or minimally come into contact) with oral soft tissues. I use metal oral spatulas to “guard” the tongue and/or buccal surfaces. Some people like the burr guards, but I have never used them as they increase the size of the equipment put in the mouth and decrease my visualization.

Are your round burrs regular length or extra long?

Regular length will be appropriate for most cases, although occasionally you get those giant rabbits and an extra-long might be nice to have around.

 

In cases of rabbit gingival overgrowth/hyperplasia due to chronic dental disease, do you also cut away the excessive gingival tissue and reduce the teeth length to as close to normal as possible?

I have never personally seen gingival overgrowth in rabbits, although I do see it frequently in chinchillas. In those cases, yes, removing as much of the overgrown gingiva is important as well as reducing the crown heights.

Treatment/management suggestions if the dental disease has progressed into a fistula? 

These cases are awful and luckily I have only dealt with a few. Like oronasal fistulas in other species, a flap closure is the best path forward. I have successfully done this in one oronasal fistula that was sequelae to the first premolar extraction. The closure was NOT pretty, but it held and the rabbit did great (minus its long term dental disease, of course!). The site only needed minimal debridement and I’m pretty sure the ability of the rabbit to wall off and fibrose things down is the only thing that saved me! I am not sure that I have the dexterity or the instruments to do one that is more caudal in the oral cavity however, with the right instrumentation (likely endoscopic equipment) and the surgeon who knew how to use those endosurgical instruments, I think it would be doable. I think if I had a case that I could not close I might consider some of the dental antibiotic infused gelling agents to infuse into the area. I know there is a doxycycline one and I think there are others, it may “fill” the area and give you enough time for the rabbit to do some more healing.

What is your approach for chinchillas with resorption?

Please visit LafeberVet’s “Dental Caries in Herbivores” by Dr. David Crossley. 

Editor’s note:  The online post is temporarily unavailable but a PDF version can be downloaded.

 

  • Should euthanasia always be discussed if owner is not ready to do dentals every few months?

Dental disease is complex and the initial diagnosis requires a big discussion with the client about expected progression and the dedication required (financially, time-wise, etc.).

At what point do you feel treatment may not be in the best interest of the animal? If there is significant bony remodeling do we know we can resolve the condition adequately for good quality of life?

This is really based upon the case, the client, and the animal. There are some animals that present with minimal clinical signs and have severe boney remodeling while others have minimal boney changes or pathology and aren’t eating! 

Dental disease is complex and the initial diagnosis requires a big discussion with the client about expected progression and the dedication required (financially, time-wise, etc).

 

Do you use polymethyl methacrylate (PMMA) pearl and antibiotics?

I am not a big proponent of antibiotic induced PMMA beads, but have used them on occasion. I only use beads when lead by culture and sensitivity results and for patients/clients where marsupialization is not an option.

In general, PMMA beads should never be a replacement for adequate debridement, flushing, etc and when used properly can be very successful. They are just not my preferred method of therapy.  

How would you place a bead in a sinus? Transdermal?

The sinuses of rabbits are enclosed in bone and require a surgical approach to enter. There is a recent paper describing the anatomy:

Summa NM, Sanchez-Migallon Guzman D, Keller KA, Woods SJ, Hawkins MG, Hunt GB. Bilateral pararhinotomy with middle meatal antrostomy of the maxillary sinus in a rabbit (Oryctolagus cuniculus) with chronic rhinitis. J Am Vet Med Assoc. 2019 Jun 1;254(11):1316-1323. doi: 10.2460/javma.254.11.1316. PMID: 31067176.

Rabbit with unilateral sinus discharge, no asymmetry, palpation is normal, maybe slight discomfort. Would a sinus bead be an acceptable treatment or only temporary postponement?

Best practice would be to determine the root cause of the infection. If the infection is associated with odontogenic abscessation, then going after that surgically would be ideal. If not associated with dental abscessation, obtaining a culture and sensitivity from a surgically sourced sample and performing adequate debridement is the ideal course.

 

I have a question regarding the guinea pig antibiotic choice in the quiz. The answer was metronidazole and enrofloxacin combo, but I thought one of the slides said chloramphenicol had superior results on culture and sensitivity? Enrofloxacin was a poorer choice? Thank you for clarifying.

There is a great paper on it that is specific to guinea pigs

Minarikova A, Hauptman K, Knotek Z, Jekl V. Microbial flora of odontogenic abscesses in pet guinea pigs. Vet Rec. 2016 Oct 1;179(13):331. doi: 10.1136/vr.103551. Epub 2016 Jun 23. PMID: 27339145.

Rabbits have their own literature that indicates chloramphenicol is the best antibiotic (in some of the papers) however, chloramphenicol was not evaluated in [the Minarikova] paper.  

How long have you kept these long-term dental cases on antibiotics?

I have had several patients on 6 months of antibiotics to treat their odontogenic abscessation. I have seen a few cases of suspected chloramphenicol-induced anemia, so just stay vigilant in those cases.  

 

An associate and myself have been considering and debating the effectiveness of a scenario regarding cases of acquired dental disease where you have lacrimal duct occlusion from overgrown roots, mainly from upper incisors.  We’ve been investigating the anatomy of the incisors and the periodontal ligament and how they function in teeth that are continuously growing.  The question is, would it be possibly to break these ligaments, in a similar manner as when extracting the incisors, but instead of extracting the incisors you pull them out a slight bit (maybe a couple millimeters), then wiring or somehow binding the upper incisors together, thus allowing the ligaments to “regrow” an hold those teeth in the newly placed position?  The theory being that you would be sliding the incisor root away from the lacrimal duct and thus alleviating the obstruction and re-establishing patency in that duct.     

Does Dr. Keller have any knowledge or experience with anything like this?  Have there been any studies or research done on any procedures such as this?  I’d be very interested in Dr. Keller’s thoughts and opinions (and anyone else’s for that matter) of this.

Very interesting thoughts to a complex problem. Overall, the most likely cause of nasolacrimal duct obstruction (partial or complete) is not secondary to incisor apical overgrowth, but instead due to premolar, molar overgrowth. In addition, I think that performing the technique you are describing would having a high likelihood of causing damage to the germinal tissue of the tooth, which is a predisposing factor to developing elodontomas. Sorry, I don’t think this approach will work…  

Not sure your approach to these cases, but happy to share mine. In general, rabbits that have nasolacrimal (NL) duct obstruction will never be normal again, even if you extract the tooth, there are still boney changes that persist. Management of the cases involves using topical NSAIDs one to two times daily, cleaning face with warm wet facecloth 1-2 times daily and performing some clipping of hair around the eye. The goal is to keep the site from getting infected. I often see them back at least quarterly (usually when doing their occlusal adjustments) and at that time perform a NL duct flush and cytology to ensure that there is no infection. I have many clients very happy with this approach and the rabbits are comfortable and not suffering from periocular dermatitis.

 

What are cost ranges for procedures?

I think pricing should be based on your market (rural, suburban, urban) and the amount of time it takes you to perform the procedure. In private practice in urban Denver, CO (USA), I charged ~$65 USD per 15 minutes of procedure time. Most first-time procedures would take me 20-30 minutes and most follow up occlusal adjustments would take me 15 minutes. The reduced amount of time was because I already “knew” the mouth and where the problem areas were. If I was doing any extractions, it was based upon time spent as well and charged similarly, I think my extraction costs were $75 per 15 minutes. These costs were all on top of anesthesia, day boarding, examination fees.

 

Miscellaneous

Is there an appropriate angle for the molars or premolars in a coatimundi?

A coatimundi has brachydont (carnivore) dentition that are not ever-growing like the hypselodont dentition of rabbits and large rodents. Thus, the occlusal plane should not be manipulated in the treatment of dental disease, but instead their dentition is treated similarly to other carnivores.

 

 

RACE approval

This program 840790 is approved by the American Association of Veterinary State Boards (AAVSB) Registry of Approved Continuing Education (RACE) approval to offer a total of 2.00 CE credits to any one veterinarian: and/or 2.00 veterinary technician CE credit. This RACE approval is for the Medical Category using the delivery method of Non-Interactive-Distance. This approval is valid in jurisdictions which recognize AAVSB RACE; however, participants are responsible for ascertaining each board’s CE requirements. RACE does not “accredit” or “endorse” or “certify” any program or person, nor does RACE approval validate the content of the program.

To cite this page:

Keller K. Rabbit and large herbivorous rodent dental disease. LafeberVet web site. March 22, 2021. Available at https://lafeber.com/vet/rabbit-and-large-herbivorous-rodent-dental-disease/