The common frog (Rana temporaria) is Britain's most familiar amphibian, yet its welfare faces threats from chytridiomycosis — a fungal disease that has caused devastating amphibian declines globally. UK populations have shown varying responses to the disease, with some garden pond populations severely affected.
Frogs dying from ranavirus infection develop haemorrhagic skin disease, red lesions on the underside, and systemic organ failure that causes death within days. Mass mortality events in garden ponds — where dozens to hundreds of frogs die simultaneously — create acute welfare emergencies. Chytridiomycosis causes keratin disruption in the skin, impairing osmotic balance and causing cardiac failure. Wildlife organisations recommend removing dead frogs and disinfecting equipment moved between ponds. The welfare of surviving frogs in affected populations is uncertain — sub-lethal infection effects on immune function and behaviour are poorly understood in UK populations.