Common Frog Ranavirus: Detection and Reporting

Ranavirus causes mass frog mortality in garden pond populations. Understanding detection, reporting and the limits of intervention protects remaining populations.

Key Facts

Ranavirus causes haemorrhagic disease in common frogs with population-level mass mortality
Signs include skin ulceration, reddening and bleeding at the base of the legs
The virus spreads through pond water, infected frogs and contaminated equipment
No treatment is available — prevention through maintaining pond hygiene is the only intervention
The Garden Wildlife Health scheme coordinates monitoring and provides diagnostic support

Welfare Considerations

Individual frogs with ranavirus experience haemorrhagic disease that causes acute suffering before death. Mass mortality events — tens or hundreds of frogs dying within days — represent population-level welfare crises. The welfare response is to prevent future spread through rigorous hygiene rather than treating affected individuals. Equipment used in affected ponds should not be used in other ponds without thorough disinfection. Translocation of frogs, spawn or pond water between sites should be avoided entirely as this represents the primary spread mechanism. Long-term monitoring after outbreaks tracks whether the local population recovers.

What You Can Do

Report mass frog deaths between February and June to the Garden Wildlife Health scheme
Photograph dead frogs and collect samples (gloves essential) if requested by GWH scheme
Disinfect all pond equipment with F10 or 10% bleach solution if ranavirus is suspected
Never move pond water, spawn, tadpoles or frogs between ponds
Monitor pond recovery annually and report results to Garden Wildlife Health