Bearded dragons are asymptomatic carriers of Salmonella.

Bearded dragons are asymptomatic carriers of Salmonella.

In November 2020, 18 people infected with an outbreak strain of Salmonella were reported from 11 different states in the United States (thankfully there were no deaths!) [1]. Further evidence unveiled that contact with pet bearded dragons was the likely source of the outbreak [1]. Salmonella infections are zoonotic in nature, making them not only a veterinary health concern, but also a public health concern. While salmonellosis can affect a wide range of animals including birds, reptiles, amphibians, poultry, swine, cattle, and horses, this article will be focusing on how to diagnose Salmonella infections in bearded dragons, which are the most popular pet reptile [2].

The good news is that even if your bearded dragon is a carrier of Salmonella, your pet will likely be asymptomatic for life. However, it is important to test your pet’s stool in order to prevent infection for humans in the household. The even better news is that the transmission of Salmonella from bearded dragons to humans can easily be prevented with simple measures!

What is Salmonella?

Salmonella is a rod-shaped Gram-negative bacteria of the family Enterobacteriaceae, that has two species and six subspecies, which are divided into over 2,600 serotypes [3, 4]! In short, there is a great deal of variation between different serotypes of Salmonella that have been found to impact transmissibility and severity of infection in humans. In contrast to the human microbiome, the bearded dragon gut microbiome frequently hosts Salmonella [4]. These bearded dragons are considered clinically healthy, because Salmonella is actually a normal contributor to the reptile gastrointestinal flora [5].

In a study assessing the prevalence of Salmonella serotypes isolated from reptiles in Norwegian zoos, researchers found a 67% prevalence rate in lizards, 62% prevalence rate in snakes, and a 3% prevalence rate in chelonians [6]. These rates are notably only indicative of the prevalence of Salmonella in reptiles shedding the disease; considering the intermittent nature of Salmonella and how shedding of the bacteria may not occur with every stool sample, these numbers are likely underreported. Moreover, a total of 26 different serotypes were discovered, including Salmonella enterica spp. enterica and Salmonella enterica spp. arizonae, both of which have a high transmissibility rate to humans [6]. Other serotypes like S. enterica spp. diarizonae, salamae, and houtenae were also identified, but these have considerable lower transmissibility potential, making it clinically advantageous to know different serotypes when assessing transmission risks [6].

Bearded Dragons and Salmonella

The image above depicts a healthy bearded dragon in a well-maintained terrarium.

Preventing Transmission of Salmonella Between Your Pets (And You!)

If your bearded dragon tests positive for Salmonella, it is extremely important to isolate your pet from other pets to prevent further transmission of the bacteria. In general, good animal husbandry can help prevent transmission of infections and shedding of pathogens. As the Manual of Exotic Pet Practice puts it, “the majority of diseases observed in captive reptiles are directly associated with improper husbandry” [7]. Notably, Salmonella is different in reptiles due to its asymptomatic nature. However, the Association of Reptile and Amphibian Veterinarians recognize that stress and compromised immune systems increase the rate of shedding in bearded dragons, making proper husbandry an important factor in decreasing transmission of Salmonella between bearded dragons and humans [8]. A proper diet is very important in maintaining optimal health for your reptile, as vitamin deficiencies can leave your reptile vulnerable to pathogens. And while it may seem obvious that cleaning your pet’s terrarium is important in warding off infections, cleanliness cannot be overstated.

Moreover, the CDC has several recommendations that every bearded dragon owner should follow, especially once a positive Salmonella cloacal test has occurred [1]. These recommendations include:

1. Pick the right pet for your family: reptiles and amphibians are not recommended for families that have children under 5 years old, adults over 65 years old, or people with weakened immune systems.

2. Wash your hands: always wash your hands thoroughly with soap and water after touching, feeding, or caring for your pet. Supervise handwashing for children.

3. Keep it clean: keep reptiles and amphibians out of the kitchen, and if you clean their supplies indoors make sure to use a laundry sink or bathtub that can be thoroughly cleaned and disinfected right after.

4. Play safe: do not kiss/snuggle/hold your reptile close to your face, do not let your scaly friend roam free in your home, and do not touch your mouth after handling your pet.

Should I Treat My Bearded Dragon if They Test Positive for Salmonella?

Nope! Once your bearded dragon is a carrier for Salmonella, they will likely always be a carrier [8]. Unnecessary antibiotic courses to eradicate Salmonella from your reptile’s gut flora actually may not only be harmful for your reptile by disrupting their natural microbiome, but may also create antibiotic-resistant strains of Salmonella that can become even more harmful should it transmit to a human. To underscore, Salmonella is not harmful for your pet, but can be harmful to you. The good news is, as long as you as a pet owner follow CDC guidelines, the transmission of Salmonella from your bearded dragon to you is much less likely.

Diagnosing Salmonella in Reptiles

Because Salmonella is zoonotic, it is important to make sure your reptile is visiting their exotic pet veterinarian once a year to test for various infections. Historically, culture-based methods have been used to assess the possible Salmonella presence, but there are notable diagnostic shortcomings. Next-Gen Sequencing (NGS) has provided superior detection capabilities for Salmonella, due to its ability to reliably predict Salmonella serotypes [9]. One study determined that using NGS “as the sole method for Salmonella serotyping can have numerous advantages as it allows for very quick and accurate serotype predictions, detailed genetic information (antimicrobial resistance and virulence), significant budgetary savings, and reduced labor requirements” [9]. The clinical applicability for bearded dragon pet owners is significant and should be brought up with your exotic pet veterinarian.

Despite its name, the MiDOG All-in-One Microbial Test may provide the answer to the diagnostic conundrum that Salmonella poses for you and your reptile. Utilizing NGS technology to detect and quantify all microbial DNA through untargeted and comprehensive sequencing and quantitative comparisons to reference databases, the MiDOG NGS technology provides a useful opportunity to shed light on the microbial makeup of your reptile’s fungal infection for clinical application. The MiDOG microbial test is grounded on scientific research that provides veterinarians DNA evidence for the guided treatment of reptile infections, such as salmonellosis.

 

MiDOG Swab Collection Kit

 

Find out if your vet uses MiDOG before you book your next appointment!

For health-related questions about your reptile or other exotic pet, reach out to a veterinarian that specializes in exotic pets.

References:

[1] CDC. 2022. Salmonella Infections Linked to Pet Bearded Dragons. [online] Available at: <https://www.cdc.gov/salmonella/muenster-10-20/index.html> [Accessed 30 March 2022].

[2] Valdez, J., 2021. Using Google Trends to Determine Current, Past, and Future Trends in the Reptile Pet Trade. Animals, 11(3), p.676.

[3] Giannella RA. Salmonella. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Chapter 21. Available from: https://www.ncbi.nlm.nih.gov/books/NBK8435/

[4] Ogunremi, D., Dupras, A., Naushad, S., Gao, R., Duceppe, M., Omidi, K., Márquez, I., Huang, H., Goodridge, L., Lévesque, R., Hasan, N., Dadlani, M., Dixon, B., Magierowski, S. and Masson, L., 2020. A New Whole Genome Culture-Independent Diagnostic Test (WG-CIDT) for Rapid Detection of Salmonella in Lettuce. Frontiers in Microbiology, 11.

[5] Diver, S., 2020. Bacterial Diseases of Reptiles – Exotic and Laboratory Animals – MSD Veterinary Manual. [online] MSD Veterinary Manual. Available at: <https://www.merckvetmanual.com/exotic-and-laboratory-animals/reptiles/bacterial-diseases-of-reptiles> [Accessed 30 March 2022].

[6] Bjelland, A., Sandvik, L., Skarstein, M., Svendal, L. and Debenham, J., 2020. Prevalence of Salmonella serovars isolated from reptiles in Norwegian zoos. Acta Veterinaria Scandinavica, 62(1).

[7] Deczm, M. M. D. M. P. & Tully Jr. DVM MS DABVP (Avian) DECZM (Avian), Thomas N. (2008). Manual of Exotic Pet Practice (1st ed.). Saunders.

[8] https://arav.org/salmonella-reptiles-amphibians-veterinary-guidelines/. 2018. Salmonella in Reptiles and Amphibians. [online] Available at: <https://arav.org/salmonella-reptiles-amphibians-veterinary-guidelines/> [Accessed 30 March 2022].

Ibrahim, G. and Morin, P., 2018. Salmonella Serotyping Using Whole Genome Sequencing. Frontiers in Microbiology, 9.


Categories: Bearded Dragons, Exotic Pets, Next-Gen DNA Sequencing Technology, Reptiles/Amphibians

animal diagnostics

Validated by Veterinarians

“Clients expect their veterinarians to stay up to date on all matters that affect the health and well being of their non-human family members. The current technique that we have used to determine the presence and antibiotic sensitivity of organisms causing disease in our pets is over a century old.

With the emergence of dangerous antibacterial resistance, it is critical that veterinarians are able to offer laser focused diagnostics and treatment. MiDog enables us to offer care that exceeds the typical standard of care.”

Bernadine Cruz, DVM, Laguna Hills Animal Hospital Laguna Woods, CA

“I love the absolute abundance and comparing the fungal with bacterial infection. I do not worry as much about getting a false negative urinary infection reading as I do with traditional urine cultures. Several times the same urine would culture negative but MiDOG would detect pathogens.”

Michael Morgan, DVMQuail Animal Hospital, Tustin, CA

“The MiDOG All-in-One Test is amazing, I would use it instead of culture and sensitivity.  Such rapid and detailed results, I will reach for MiDOG before culture next time!

Thank you very much MiDOG, for sharing the opportunity to try your technology.”

Martha Smith-Blackmore, DVM, President of Forensic Veterinary Investigations, LLC – Boston, MA

The MiDOG All-in-One Microbial Test is our new gold standard of pathogen identification. The results are so accurate and valuable – especially with assessing both bacterial and fungal infections with the same sample.

Thank you MiDOG!”

Kathy Wentworth, DVM, Diplomate ABVP Canine and Feline Practice – PetPoint Medical Center, Irvine, CA

“The MiDOG staff was extremely helpful and supportive.”

Cathy Curtis, DVM – London, UK

“I have had great results using the MiDOG® Test. Compared to traditional culture tests, I am better able to target the treatment for dogs because the MiDOG® Test is so sensitive that it identifies all pathogens including bacteria and fungi, as well as antibiotic sensitivity.

The cost and turnaround time are about the same as a culture test, but I get much more data. The test has great performance and I believe the NGS technology will be a game changer for veterinarians treating dogs with lesions or other infections.”

Michael Kavanagh, DVM, Practice owner – Saddleback Animal Hospital, Tustin, CA

“It’s helpful to have an NGS spectrum because it gives you a broader insight of what’s happening and what might be going on.”

Richard Harvey BVSc DVD DipECVD PhD FRSB FRCVS – European Specialist in Veterinary Dermatology – Head of Dermatology, Willows Veterinary Centre & Referral Service – Solihull, England UK

“I have been using MiDog for over 4 years now and exclusively as my test of choice for all cultures for 3 years.  It is so great to submit a culture and feel confident there will be a result when it comes back, especially for urine cultures.  The reports were intimidating at first because they contain so much information.  After the first few, I am now quickly able to glance over it and pick out the highlights.  I can then come back later and pour over all the details.  I have been extremely pleased with my patients’ results using the test as well.  I don’t envision ever going back to traditional culture and susceptibilities again.”

Brian M. Urmson, DVM, Columbiana Veterinary Associates

“As an exotic veterinarian, there are numerous tests we have to consider to check specific bacterial and fungal organisms based on the species. MiDOG eliminates the need for many of these separate samples and provides definitive results quickly to help us treat our patients more efficiently and effectively. The lab is wonderful to work with and has never rejected our samples- they even processed a lizard toe we amputated and determined the cause of skin infection.”

Dr. Melissa Giese, Chicago Exotics Animal Hospital

“MiDOG’s diagnostic approach offers the unique ability to identify pathogens that evade traditional culture and sensitivity testing. I have found that adding a molecular based testing approach in the form of Next Generation Sequencing (NGS) from MiDOG to my routine diagnostic cultures can be extremely helpful in the identification and diagnosis of uncommon pathogens in veterinary medicine.”

Dr. Wayne Rosenkrantz, Animal Dermatology Clinic – Tustin

“She [Dr. Krumbeck] really did a great job of making complicated concepts accessible and demonstrating the value of your services. I’m really looking forward to working with MiDOG on my research project!”

Dr. Yaicha Peters, Animal Dermatology Clinic – San Diego

“As a proud collaborator with MiDOG, I deeply appreciate their dedication to fostering partnerships between industry and veterinary experts. Their commitment to enhancing diagnostic quality for veterinarians is commendable. In my experience, their support has been invaluable, earning them a ‘Double A+, Triple Star’ rating. Their assistance has been faultless, contributing significantly to the success of my projects and studies. I eagerly anticipate our continued collaboration.”

Dr. Richard Harvey, BVSc DVD DipECVD PhD FRSB FRCVS; European Specialist in Veterinary Dermatology

“We’re seeing that, if we prescribe too many antibiotics or they’re taken too frequently, animals are developing inappropriate or pathogenic strains of bacteria. We’re also seeing that our antibiotics are just not working against them anymore… It’s a good example of why we need better diagnostic testing, like MiDOG, so that we’re selecting the correct antibiotic every time our patients have an infection.”

Dr. Alissa Rexo, DVM, CVA, DACVD, Mid-Atlantic Veterinary Dermatology

“The NGS technique as offered by MiDOG is wonderful because pathogens like Melissococcus plutonius, for example, are difficult to grow and keep alive in the laboratory. A standard laboratory cannot truly examine or even properly diagnose this pathogen in bee hives at this time. But with NGS, we can reliably diagnose it.”

Dr. Joerg Mayer, Entomologist and Microbiologist at the University of Georgia

“For me, as a clinician and as a researcher, I see the immense value in the product [the All-in-One Test]. I have had great success using MiDOG clinically, including identifying Mycoplasma in a 24 year old pigeon, a Nannizziopsis spp in a ball python from a large pet distributor, Mycoplasma and Fusobacterium necrophorum co-infection in a peacock, and to identify an abnormal gut GI in a technician’s dog that tested negative for everything else (but we were able to establish what was abnormal, and work toward fixing it).”

Dr. Jeremy Rayl – Veterinarian, Block House Creek Animal Hospital, Cedar Park, Texas

“With MiDog results I not only receive a list of organisms detected in the sample, but also cell counts which allow me to target the most abundant pathogens or the most pathogenic. The identification of antimicrobial resistance genes is also helpful in selecting an appropriate antibiotic. Another benefit is that sample handling is less prone to risk of overgrowth and is stable at room temperature. Easy and informative. A great tool in our diagnostic toolbox!!”

Lauren Palmer DVM, MPH, Marine mammal Care Center Los Angeles