By Ash Gelhaus, Sierra Scales Exotics

Image Content Warning: Images depict real snapshots of a snake infected with Nidovirus. Some images may be disturbing to young children or those who are sensitive. Viewer discretion is advised.

Nidovirus, also known as serpentovirus, is a formidable RNA virus that poses a significant threat to reptiles, particularly snakes and lizards. Identified in 2014, this virus has been linked to severe and often fatal respiratory infections in these animals. Identified in 2014, it's still a relatively new topic in the reptile community, but its impact has been devastating. Many reptile keepers avoid discussing it, as if saying its name will invite it into their collections. Unfortunately, nidovirus is very real, and it will kill if given the chance. This is the story of how it changed my life and my approach to reptile keeping forever.

Ember

My introduction to nidovirus came in late March 2022, when one of my 15 ball pythons, Ember, started showing signs of a respiratory infection (RI) out of nowhere. I could hear the tell-tale clicks and wheezing sounds when she breathed, her saliva was bubbly, and her appetite quickly faded. This wasn’t my first experience with an RI — I had helped my “rescue” ball python, Meeko, through a particularly stubborn RI the year before — so I took Ember to the vet right away. The vet agreed it was likely a typical RI and prescribed a month of subcutaneous antibiotic injections.

By mid-April, despite faithfully following the treatment plan, Ember's condition rapidly worsened. Thick mucus collected in her mouth and was builing up on the outside of her mouth crusting up, and her breathing had become even more labored. I scheduled an emergency follow up with the vet, who prescribed a stronger antibiotic. While treating Ember with the new antibiotic, I began researching online, desperate for answers because deep down something about this RI didn’t feel right. In my search I stumbled across an episode of the Holdback Rack Podcast that discussed nidovirus, I had never heard of it before, but the symptoms they described were chillingly familiar.

Still seeing no progress after two weeks of the stronger antibiotics, I decided to test Ember for nidovirus in May. I ordered a test and swab from Fish Head Diagnostics, but a shipping delay from UPS caused the sample to arrive at the lab late, instead of overnight, compromising the sample. When the results finally came back, they were negative. I wanted to feel relief, but with the delay and summer temperatures I felt doubtful it was accurate, and had a gut feeling it was a false positive.

By June, Ember was deteriorating quickly, my sweet snake that used to be super curious and interactive had become listless and swollen. She had begun to prop her head up on her water bowl or hide — a behavior that snakes sometimes use to make it easier for them to breathe by keeping the mucus out of the esophagus. Her usually slender but healthy body was now so bloated with air she resembled a balloon used to make balloon animals. I had to wipe the crusty mucus build up from the sides of her mouth daily, and I had started using q-tips to gently scoop out as much mucus as I could every few hours. I brought her to the vet again, at this point for any last-ditch effort, I needed to make sure I had tried EVERYTHING in my power. This time, we took a bacterial culture to see if there was a bacterium we could specifically target. I mentioned my suspicions of nidovirus, but the vet wasn’t familiar with it and promised to research it and consult with other exotic vets out of our rural network to see if anyone else had any experience with it. I ordered a new nido test kit, this time from Research Associate Laboratories, a closer lab just to be safe.

The culture results from the vet showed an unusual bacterial infection not typically seen in reptiles — which as it turned out was a secondary infection that took advantage of her weakened state. Despite targeted antibiotics, her condition somehow spiraled even worse. She started breathing exclusively through her gaping mouth, her eyes grew cloudy and lost all the light and vibrance they once had. Her poor body was so swollen that it was stretching so much I could see the skin between her scales. I knew in my heart she was done fighting, and this was not a battle either of us could win. I scheduled a euthanasia appointment for the following week because it was Friday, and no exotics vet was open until Monday.

But she didn’t make it to Monday. Ember passed away the next day, and I was beyond devastated, but relieved she was no longer suffering. That same day, the new nidovirus swab I had ordered arrived. I took a sample from Ember's mouth and esophagus and sent it to the lab. This time, it was shipped overnight and processed quickly. The results came back — positive for nidovirus — my heart sank. Even though I had suspected it, seeing it in writing was different, and my mind raced immediately to thoughts about potential spread to my other snakes. Nidovirus is notorious for its high prevalence and persistent infections in pythons, often leading to increased mortality rates. Studies have shown that this virus can spread rapidly within captive snake collections, underscoring the critical importance of biosecurity measures. I wondered why no one in the reptile community talked about this? Why didn’t I know about it when I first started keeping ball pythons three years prior? I did my homework, i learned everything I could to make sure my husbandry and keeping standards were on par with the newest reccomendations. I cared deeply about every animal in my collection, and it all hit me like a brick. I was in shock, it felt like a nightmare I couldn’t wake up from, and it only got worse.

Instead of letting the feelings of hopelessness and guilt run me into the ground, I decided to be proactive and ordered tests for all my remaining snakes. When the results came back, I braced myself. I knew the chances my entire collection could be infected were very high. I opened the emailed results: fifteen out of sixteen tested negative. The exception was Meeko, the “rescue” ball python I had taken on the year prior. That familiar heart sinking feeling set in again.

Meeko

Rewind to May 2021, when Meeko was offered to me from a supposed “reptile rescue" my mom had found in her search for a bearded dragon. Advertised as a healthy, proven breeder male mojave ball python with a very reasonable adoption fee, I proceeded, even though I had reservations. I went with my mom to the “rescue” which was about a two-hour drive away. The moment we arrived, I knew something was wrong, all the signs of a hoarder situation were presented to my mom and me. We weren’t allowed to see the enclosures or enter the house, but the stench of waste, long dead crickets, and decay spilled through the open door.

When Meeko was handed to me, I immediately noticed several layers of stuck eye caps and he had mites crawling openly across his scales. I should have handed him back and walked away, I should have listened to my gut. But my empathy won out — I couldn't leave him there knowing what suffering he would be going back to. My mom, equally compassionate, adopted a severely ill bearded dragon named Frankie from the same place, the beardie had obvious signs of a respiratory infection.

I quarantined Meeko immediately, far from my other reptiles. It took several days to treat the mites, using a combination of soaks in dawn dish soap baths and very small amounts of Provent-a-Mite removed. His layers of retained eye caps were thick and took several sheds to remove, and unfortunately one eye was permanently damaged and now blind. There were several somewhat fresh scabs along his spine from what looked like a rat nibbling on him or burns. I treated those for two weeks with silver sulfadiazine cream and scheduled a vet visit to address his subtle wheezing. As suspected Meeko had a respiratory infection, which ended up requiring multiple rounds of antibiotics, six months of quarantine, and several hundred dollars in vet fees.

After what felt like forever, Meeko finally seemed healthy, aside from permanent eye damage from the stuck eye caps. After an additional couple weeks quarantine for good measure, I integrated him into the rack that housed my main collection in February 2022.

That same evening, it was very late, and I was incredibly tired, but I was cleaning tubs and doing water changes and when cleaning Ember's tub, I mistakenly placed her in Meeko's tub without realizing it at first. when I came back with the freshwater bowl, no more than five minutes later, I realized my mistake. Both animals appeared healthy, so I dismissed the brief interaction as inconsequential. Tragically, this brief contact was enough for nidovirus transmission. Nidovirus can spread through direct contact and contaminated surfaces, making strict biosecurity measures essential. That small biosecurity mistake cost Ember her life

Hard Lessons, Harder Choices

The nidovirus test results in June 2022 revealed the source of Ember's infection. Meeko, despite appearing healthy, was an asymptomatic carrier—a common and insidious characteristic of nidovirus, similarly to Covid-19, it can be carried in a body with no indication it is there but it can still be spread. This revelation was heartbreaking.

Nidovirus cannot be cured, and it was very clear that Meeko could not stay in my house with all the other reptiles I had, I could nopt risk what happened to Ember ever happening again. After a week of consulting with other ball python breeder friends, calling around to different research labs, schools, and doing even more research, I struggled with deciding what to do with Meeko. Neither option I was presented with felt right. There was no one taking infected ball pythons for research which was my preferred option. So, I was left with the impossible decision of euthanasia or rehoming him to a reptile free home to live out the remainder of his life. I opted to rehome him to a friend without other reptiles, fully informed of his condition, the friend and his kids were super excited to love on Meeko and give him the best life they could. Unfortunately, after a year of dedicated care, Meeko began exhibiting nidovirus symptoms and was humanely euthanized before it could progress any worse.

Remember Frankie, the bearded dragon my mom adopted from the same "rescue" that displayed severe respiratory issues akin to Ember's? Well, despite my mom’s months of dedication to his care, extensive veterinary efforts, and multiple rounds of antibiotics, Frankie also succumbed. At the time, we were unaware that nidovirus could affect lizards, I only learned this after he passed as I was doing further research. But this is a little-known fact that highlights the virus's broader impact to the reptile community. and yet, there are still only whispers of acknowledgment of this “boogeyman”, despite its very real presence in even the least expected places.

Reflection

What do I hope to gain from writing this you may wonder. My hope is that Ember’s story and her life serve as a lesson, a teachable moment that encourages reptile breeders and keepers alike to be open and transparent about disease testing, biosecurity, and Nidovirus. Brushing it under the rug does nothing but prolong the inevitable. Some of these animals being purchased to breed and intermingle with other animals are sometimes worth thousands of dollars. Wouldn’t you want to ensure your “investment” was healthy? Wouldn’t you feel better if you tested the snake before putting it into your collection, knowing you did what you could to prevent losing it all? Money aside, if you are breeding these animals, I would hope that means you care for them at some level, which would indicate some kind of moral responsibility to ensure the animals in your possession are healthy, in addition to proper care. Admittedly, false negatives do happen, but false positives are rarer, and in general it can be assumed a positive result is likely positive, but a second test can be done if more evidence is desired.

Below is my advice to anyone wanting to avoid a nidovirus nightmare:

Test all animals upon intake. Early detection is vital to prevent the spread of nidovirus within collections.
Implement stringent biosecurity measures. Even brief interactions can facilitate transmission; meticulous hygiene and quarantine protocols are essential. If you want to go one step further, test your animals once a year.
Avoid acquiring sick animals. While compassion is commendable, introducing ill animals poses significant risks to existing collections. Even if you think you can help it, trust me, it isn’t worth the potential risk.

Adhering to these principles might have spared Ember’s life. I was fortunate not to lose my all my reptiles. This experience was something I wouldn’t wish on even my worst enemy. I care deeply for the animals in my care, I thought that I was doing it all right. This experience helped me to realize that I was not meant to breed ball pythons long term, it was a learning experience, and I made many great friends along the way. I rehomed most of my ball pythons, keeping only 7, but those 7 are healthy, tested, and thriving. And you can bet my biosecurity is 99.9% perfect now.

Let my experience serve as a cautionary tale. Test your animals. Do your research. Don’t cut corners. And most of all: be willing to learn and teach others. We are all in this hobby together, the more we learn and share the better the hobby will be.

Sources:

https://researchonline.jcu.edu.au/70115/

https://journals.asm.org/doi/10.1128/jvi.00649-20

https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.733404

https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2019.00338

https://azeah.com/reptiles-amphibians/serpentovirus-nidovirus-snakes?

Ember's Story: A Nidovirus Nightmare