Ophidian Paramyxovirus (Ferlavirus)
What is it?
Ophidian paramyxovirus (ferlavirus) is a contagious virus that mainly causes respiratory disease. It was first described in vipers but can affect many snakes. It spreads through respiratory secretions.
What signs should I watch for?
Signs to watch for include open-mouth breathing, bloody or mucus-filled discharge from the mouth, regurgitation, neurologic signs like tremors, and sudden death.
How is it diagnosed and treated?
Diagnosis uses PCR testing and blood tests. Treatment is supportive, including care for secondary bacterial infections.
Can it be prevented, and what's the outlook?
- There is no cure or vaccine.
- Quarantine and testing are the best prevention.
Reviewed by the Adler Veterinary Hospital veterinary team, October 2026.
Many snakes, first described in vipers
Who's at risk:
Open-mouth breathing, bloody mouth discharge, tremors
Main signs:
See a vet within a day or two
Urgency:
When to call a vet right away
- Open-mouth breathing
- Bloody or mucus-filled discharge from the mouth
- Tremors or other neurologic signs
Not sure whether it can wait? Call us anyway. Our team can help you decide.
Source:
Related conditions
Cryptosporidiosis
Inclusion Body Disease
Respiratory Infections