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  • Writer's pictureOzzy Boids

The MSB Blog: Nidovirus!

Disclaimer: I am not a Vetinarian or an expert on this topic. However, I have been keeping and breeding ball pythons successfully (depending on how you define success) for 21 years now. I don't expect everyone to agree with me, but I wanted to share my opinion on this topic. Consider my logic and form your own opinion.

So the past couple of years I have been hearing a lot of talk and concern around nidovirus in Pythons. I have heard about people loosing collections or sizable portions of collections. Unlike talk of nidovirus, this is nothing new. Unfortunately, these events have been occurring since I started keeping Ball Pythons 20+ years ago. Wether this was due to nidovirus or some other yet to be detected cause, I can't say. This is every collectors worst fear second only to fire. This is a risk we all have to live with and can only take certain precautions to reduce that risk knowing that we can never completely eliminate it. This is like most unfortunate things in life. Fortunately, these events are rare and with good husbandry can possibly be prevented all together.

A Brief History of IBD

Back in the day, the big scare that hit the Boa community was IBD. Several breeders were having boas get sick and showing symptoms of stargazing prior to eventually dying. These animals were being diagnosed with IBD. At the time, many believed that IBD was a certain death sentence. Years later we realized that many boas that had IBD were completely asymptomatic. They feed, breed and thrive like any other boa while other boas get sick and eventually die. Now I'm no expert on this topic and there are many professionals like DR Scott Stahl who have studied and diagnosed this disease in boa collections that know way more about IBD, but it appears that the IBD scare has mostly worked it self out. Boa breeders are still going strong and breeding some exceeding cool animals nearly two decades later. Unfortunately, at the time many otherwise healthy boas were put down simply for testing positive for IBD in an effort to eradicate the disease from ones collection. This was an overreaction in my opinion since IBD is still very much present in collections, but simply not as bad as it once was. This can be explained by a couple different theories... one being that viruses adapt not to kill off their host through natural selection. When the host dies, the virus usually dies too and can not propagate and continue to spread. Another theory is all the prone boas were wiped out leaving only the resistant boas around eliminating the frequency of mortality when a boa is exposed to IBD. Either way, a terrifying issue appears to have sorted itself out. I suspect the same will happen with Nidovirus... eventually, it will turn out to not be that big of a deal.

Is Nidovirus New?

Now based on what I am hearing, here are some things to consider. Nido presents as a respiratory infection (RI). RIs have been prevalent in Ball Python collections for as long as I can remember. They were always attributed to a bacterial infection which would be treated with antibiotics like Baytril. Most of the time the snake would still end up dying. Now it is being said that the snakes are Nido positive and the bacterial infection is a secondary infection due to the snakes weakened immune system. This would explain why the antibiotic treatments were rarely effective in saving these animals since antibiotics only work on bacteria and not viruses. So maybe Nido has been present all along and just never diagnosed in all the snakes that had RIs over the years? If this is the case, then Nido is nothing new and has been present from day 1.

Should we Test?

Before I retired from corporate America, I worked as a lab technician, vaccine manufacturer and eventually a regulatory compliance guy tasked with ensuring the quality, safety and efficacy of the vaccines we manufactured. When something broke down or went wrong we would investigate and sometimes perform testing to verify the quality of a drug. A few important lessons I learned was know what you will do with the results of a test before you go testing, make sure the sampling process was sound and the test method used is reliable. Know, what you hope to gain or achieve with the test results. Based on all the talk out there about Nido, people are starting to test snakes that they purchase to make sure they are Nido free. I have even had some of my customers test snakes that they purchased from me. So people are now testing perfectly healthy appearing animals just to make sure they are Nido free. Lets take a step back here and reconsider the need for testing. Another aspect of this virus that was reported by researchers studying the virus on a Zoom call with Snakes and the Fatman about a year ago (link below) was that they were breeding Nido positive animals and their offspring were testing negative. This is very reminiscent of the issue with Boas years ago. These animals have Nido, yet they are healthy enough to go through the riggers of breeding and produce healthy offspring. Should we even consider these snakes to be sick? I have also heard this from other sources that stated outwardly healthy animals can test positive. The experts on Chris's panel stated that you could have a wildfire like infection that wipes a collection fast or a slow burn that slowly eats away at the collection. This is very interesting and goes to show that we really don't understand the effects of this virus very well. Could it be that there are several strains of Nido with some being bad, really bad or completely HARMLESS? Is the test being performed capable of differentiating between these strains or is there another explanation why we are seeing drastic differences in the health of Nido positive animals? So if you have a healthy Ball Python that tests positive for Nido, what do you do? Do you euthanize it? I say hell no. We made this mistake in the past with Boas that tested positive for IBD. Perhaps these animals are the key to building a lasting resistance to the virus or the strain that they tested positive for is completely harmless. I think it would be foolish to euthanize a perfectly healthy animals that tested positive for a virus we don't fully understand. Is this resistance to Nido genetic in nature and can it be passed down to the snake's offspring which would make this animal a tool to help keep future collections healthy? The fact of the matter is we just don't know. I think we should continue to research and try to understand what's going on here, but panicking and testing for a virus we don't even fully understand yet is a bit premature in my opinion.

I have personally never tested any new snakes that I bought. I have picked up several ball pythons and a few boas this year. I did not test any of them, because I would not treat them differently irregardless of the results. If they look sick I would return them to the seller immediately. Otherwise, I quarantine all new animals for at least 2 weeks and I inspect them closely before adding them to my collection. I check their mouths for any signs of infection, inspect their scales, perform a precautionary treatment for mites and inspect their stool. Even after adding them to my collection, I house my animals separately and watch them closely for any signs of illness. New animals are usually housed separately for months if not years before I actually pair them for breeding. These precautions have worked well for me over the years and I will continue these practices.

As far as testing being performed by the buyer, this has it's own set of problems in addition to the obvious issues highlighted above. Some other concerns I have around testing is false positives, contamination of the sample by the buyer or at the lab, exposure to the virus at the buyers facility, unreliable test methods/results, deliberate slandering or undermining of rivals by asshole breeders.

Well these are my thoughts on the topic. I look forward to hearing other points of view or opinions on this topic, but for me it will be business as usual. I am not going to panic or worry about losing my entire collection. I will do what I have been doing the past twenty years in caring for my animals and respond to problems as they arise.

Link to Snakes and The Fatman Discussion:


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Small Town Xotics
Small Town Xotics
Feb 08, 2022

I was on that zoom call and in the beginning I was entertaining the idea of systematically testing my collection. Then while we dived deeper into the topic I learned that snakes can be asymptomatic and testing isn’t entirely accurate. So I’m with you Ozzy. I believe that good husbandry and proper precautions are all I need to do for now.


Bear Harrell
Bear Harrell
Jan 22, 2022

As always, good info. Thanks.


Byron Ratliff
Byron Ratliff
Dec 12, 2021

I’m glad you addressed this issue. I was wondering what your stance was on the nido topic. I agree with you. Keep the blogs coming. Thanks Oz!!!

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