Is the Nasal Microbiome the Secret to Treating Nasal Infections in Pet Bunnies?
Did you know that one of the most common illnesses in pet bunnies has to do with arguably the cutest part- their nose? That’s right, bunny noses are actually more susceptible to infection or inflammation simply because of the way they are shaped.  Not only that but since bunnies cannot breathe through their mouths, if their nose becomes stuffy (unlike other animals), nasal inflammation in bunnies creates a pretty common and possibly life-threatening issue!
Nasal inflammation and respiratory infections in rabbits, known as Chronic Rhinosinusitis (CRS), have many symptoms that bunny owners and veterinary professionals should look out for.
What Are the Symptoms of Chronic Rhinosinusitis in Bunnies?
Runny/wet nose (nasal discharge)
Reduced airflow/heavy breathing
Slobbering or excessive saliva
Discharge from the eyes or other parts of the face
If your bunny is experiencing these symptoms, seeking medical guidance for treatment is essential! But, to develop the BEST treatments for CRS in bunnies, we need to first understand the cause of CRS.
What Causes CRS in Pet Bunnies?
Sometimes, CRS in bunnies can be due to non-infectious causes, like inhaling foreign bodies, occasional allergies, or even dental issues.
Infectious CRS, on the other hand, is linked to adverse changes in nasal bacteria or fungi. [2,3] Recent research has shown that changes to the nasal microbiome and fungal mycobiome occur when bunnies suffer from CRS. Two recent research articles have identified that bunnies with CRS show significant changes in their nasal microbiome, including increases in inflammatory pathogens like Pseudomonadales spp. and Burkholderia,  as well as reductions in commensal bacteria, like Moraxella spp. and Neisseriaceae spp. 
While no study to date has identified changes to the fungal mycobiome of bunny noses, particular infectious fungi have been shown to contribute to nasal inflammation in other animal models, including Alternaria spp. 
So, if CRS is due partly to alterations to the nasal microbiome and mycobiome, how do veterinary professionals I.D. certain bacteria or fungi that contribute to CRS?
The current identification of infectious pathogens and subsequent treatments that many veterinary professionals employ may fall short.
The good news is that the influence of the nasal microbiome and mycobiome on CRS in bunnies poses a great opportunity for veterinary professionals to update how they, 1, identify and, 2, treat these types of infections!
Identifying Bacteria That Contribute to CRS in Bunnies
Traditionally, veterinary professionals use traditional culture methods (like PCR) to identify pathogens that could be contributing to rabbit respiratory infections. While these methods can typically I.D. bacteria that could be present in your bunny patient’s nose, they don’t often show the ENTIRE picture.
For one, not all bacteria grow sufficiently well in the lab conducting the PCR technique.
Not only that, but PCR culturing can only detect the bacterial strain associated with the primer in the kit provided to the veterinary professional. For instance, if the veterinary professional suspects an Escherichia coli infection, they can request analysis for that particular marker.
Thus, while culture methods can effectively identify pre-determined, common pathogens, using this technique makes it impossible to detect uncommon or novel bacterial or fungal markers.
And, since research is so new in this area, and we don’t know which exact bacteria or fungi contribute to CRS, culture methods may fail to I.D. the most appropriate bacterial or fungal marker to target with treatment.
Effective and Accurate Diagnostic Tools for Nasal Infections in Pet Bunnies
Fortunately, more advanced technologies can (and should) be used to identify more uncommon bacterial or fungal taxa that may contribute to CRS, like next-generation sequencing (NGS).  The MiDOG All-in-One Microbial Test utilizes NGS technology to detect and quantify microbial DNA through untargeted and comprehensive sequencing and quantitative comparisons to reference databases. The MiDOG NGS technology provides a valuable opportunity to identify many more markers that could contribute to CRS with this untargeted sequencing approach. The MiDOG microbial test is based on scientific research that provides veterinary professionals with DNA evidence to treat bunny CRS more effectively and accurately!
How to Treat Rabbit CRS Infections
Typical treatments to treat CRS that target bacteria, like antibiotics, have been widely used to eliminate pathogens contributing to the infection. However, while antibiotic treatments have been successful, veterinary professionals must consider two important factors that could impact their efficacy.
1. It is essential to prescribe the most appropriate antibiotic to accurately target the specific bacterial marker contributing to the respiratory infection.
This can be difficult to do when using culturing methods, but fortunately, with the MiDOG test results, veterinary professionals can prescribe the right antibiotic.
2. Antibiotics can inadvertently alter the microbiome or mycobiome and often lose effectiveness over time.
This is known as antimicrobial resistance, or AMR. Some typical AMRs that common pathogens have include:
While respiratory infections can impact the lives of pet bunnies significantly, knowing what to look for in terms of symptoms is the first step to treating these furry friends!
Fortunately, there have been many advancements in treatments to help our pet bunnies heal from CRS. Of course, it is also important to consider other factors besides the microbiome and mycobiome, including the health history of your pet bunny.
Working with your veterinary professional and using NGS technology, like the MiDOG All-in-One Microbial Tests, is a great first step in identifying the root cause of the respiratory infection so you can optimize your treatment plan and help your bunny best!
Read More About CRS in Rabbits:
Xi J, Si XA, Kim J, Zhang Y, Jacob RE, Kabilan S, Corley RA. Anatomical Details of the Rabbit Nasal Passages and Their Implications in Breathing, Air Conditioning, and Olfaction. Anat Rec (Hoboken). Jul 2016;299(7):853-68. doi:10.1002/ar.23367
Didehdar M, Khoshbayan A, Vesal S, Darban-Sarokhalil D, Razavi S, Chegini Z, Shariati A. An overview of possible pathogenesis mechanisms of Alternaria alternata in chronic rhinosinusitis and nasal polyposis. Microb Pathog. Jun 2021;155:104905.
Damerum, A., Malka, S., Lofgren, N., Vecere, G., & Krumbeck, J. A. (2023). Next-generation DNA sequencing offers diagnostic advantages over traditional culture testing. American Journal of Veterinary Research, 84(8), ajvr.23.03.0054. Retrieved Sep 21, 2023
Mitchell, J. D., McKellar, Q. A., & McKeever, D. J. (2012). Pharmacodynamics of antimicrobials against Mycoplasma mycoides mycoides small colony, the causative agent of contagious bovine pleuropneumonia. PloS one, 7(8), e44158.
Létourneau, V., Nehmé, B., Mériaux, A., Massé, D., Cormier, Y., & Duchaine, C. (2010). Human pathogens and tetracycline-resistant bacteria in bioaerosols of swine confinement buildings and in nasal flora of hog producers. International journal of hygiene and environmental health, 213(6), 444–449.
Dai, L., Sahin, O., Grover, M., & Zhang, Q. (2020). New and alternative strategies for the prevention, control, and treatment of antibiotic-resistant Campylobacter. Translational research : the journal of laboratory and clinical medicine, 223, 76–88.