Snake Viruses (Nidovirus, IBD): Symptoms & Signs to Watch For

When your snake starts acting strange—refusing food, breathing oddly, or playing dead (and it’s clearly not their usual behavior )—it’s time to pay attention. These cold-blooded companions are masters of subtlety, which makes spotting illness a challenge. But when it comes to snake viral infections, the sooner you catch the signs, the better the odds.

From Nidovirus (also called serpentovirus) to Inclusion Body Disease (IBD), these aren’t just scary names—they’re serious threats and they’re been becoming a lot more common. If anything seems off, your first call should be to an experienced reptile vet—not your favorite herp forum.

Here’s what you need to know! 

Nidovirus: A Serious Respiratory Threat 

Nidovirus is a respiratory virus that spreads like wildfire, especially in pythons and boas. One minute, your snake may appear healthy; the next, it could be exhibiting clear signs of respiratory distress. 

Common signs include:

• Labored or open-mouth breathing

• Trouble shedding

• Excess mucus in the mouth or nostrils

• Lethargy or decreased activity

• Loss of appetite

• Swelling of the throat or upper airways

  
  

While it may start out looking like a mild respiratory infection, Nidovirus can escalate quickly and prove fatal if left untreated. The tricky part? Some infected snakes show no symptoms at all… until it’s too late. That’s why annual exams and regular bloodwork at an exotic vet are critical to ensure early detection. 

IBD: A Neurological and Systemic Danger 

Inclusion Body Disease is a severe and often fatal condition that primarily affects boas and pythons. Caused by a type of arenavirus, IBD can compromise multiple body systems, especially the nervous system.

Symptoms of IBD can include:

• “Star-gazing” (holding the head upwards)

• Poor coordination, ataxia, or inability to right itself when flipped 

• Regurgitation after eating

• Weight loss

• Muscle tremors and/or even ascending paralysis

  
  

Currently, there are no known cures for either Nidovirus or Inclusion Body Disease (IBD) in snakes. For both of these serious viral infections, the focus of veterinary care is on supportive measures to alleviate symptoms and prevent secondary complications. Unfortunately, these diseases can be severe and often fatal, highlighting the critical importance of preventative measures such as strict quarantine protocols and regular veterinary check-ups.

Have a Ball Python? Curious about what else could be affecting him/her? Check out our blog on the Most Common Health Concerns – Ball Python for more signs and symptoms to watch for.

How These Viruses Spread 

Nidovirus and IBD aren’t passed through bites or casual contact alone. They hitch rides on shared tools, water bowls, infected bedding and substrate, feeding tongs, and even your hands and clothing. That’s why proper hygiene and quarantine practices aren’t optional—they’re essential.

Even seemingly healthy snakes can be carriers. For this reason, strict quarantine procedures for new or returning animals are critical. Ideally, new snakes should be quarantined for a minimum of 60–90 days and tested for viral infections before being introduced to your existing pets.

If you're attending reptile shows, buying from pet stores, or adopting rescues, assume that any new snake could be a carrier—even if it appears healthy.

Diagnosing the Invisible

These diseases can’t be diagnosed based on symptoms alone. Proper diagnosis requires advanced veterinary diagnostics, such as:

• PCR (Polymerase Chain Reaction) testing for viral RNA

• Serology testing for antibodies of the virus

• Biopsy in some cases

• Imaging if neurological symptoms are present

  
  

That’s where we come in. At Long Island Bird and Exotics Veterinary Clinic (LIBEVC), we know reptiles and we have extensive experience in diagnosing and treating exotic pets, including snakes with suspected viral illnesses. Our team uses specialized testing protocols and evidence-based care strategies to help identify and manage these complex diseases early. 

When in Doubt, Slither to the Vet

Is your snake looking different? Acting strange? Seeming “off”? It might be time to consult your exotic vet. Not sure what your snake’s symptoms mean? Contact LIBEVC for expert guidance on testing, diagnosis, and care.

Want to brush up on the basics while you’re at it? Don’t miss our Snake Care Guide for tips on keeping your slithery companion healthy and stress-free year-round.

Give Us a Call!