Batrachochytrium salamandrivorans: how to spot and report the disease
How to spot Batrachochytrium salamandrivorans, what to do if you suspect it and measures to prevent its spread.
Applies to England
Batrachochytrium salamandrivorans (Bsal) is a chytridiomycete fungus that causes the lethal skin disease chytridiomycosis (chytrid disease) in amphibian species. It mainly affects salamanders and newts.
It does not affect humans.
Batrachochytrium salamandrivorans (Bsal) is a notifiable animal disease. If you suspect this disease you must report it immediately by calling the Defra Rural Services Helpline on 03000 200 301. Failure to do so is an offence.
Bsal was first detected in wild salamanders in Europe in 2013. It was most likely introduced to Europe through trade in captive amphibians from South East Asia to Europe, where it then spread from the captive to the wild salamander population.
Since its introduction to Europe, Bsal has caused mass mortalities in wild salamanders in Belgium, Germany, the Netherlands and Spain. In Great Britain (GB), it has been recorded in captive populations of amphibians but not yet in wild populations.
Bsal is pathogenic for most western Palaearctic salamander and newt taxa, including the GB protected species the great crested newt. It’s considered a major threat to amphibian biodiversity.
How to spot Bsal
Bsal is only known to cause disease in salamanders and newts, although some frogs and toads can carry the fungus without showing any clinical signs.
Chytrid disease is characterised by multifocal superficial erosions and extensive epidermal ulcerations all over the body.
Clinical signs can include:
- excessive shedding of the skin
- anorexia
- apathy
- ataxia
- death
Confirmatory laboratory tests are needed to confirm the presence of Bsal - you cannot confirm from clinical signs alone.
How Bsal is spread
Bsal can be spread by:
- direct contact between animals
- contaminated materials, such as water, equipment, soil, gravel and aquatic plants
It can also persist in the environment without amphibians for at least several weeks.
Preventing and controlling Bsal
You can help prevent the disease from spreading between captive and wild populations in GB by practising good biosecurity.
If you keep or breed salamanders or newts, or are involved in amphibian fieldwork you should:
- dispose of waste water and other materials safely
- prevent the escape or release of potentially infected animals - it’s an offence to release or allow to escape any non-native amphibian into the wild
- cleanse and disinfect people and equipment which have been in contact with amphibians or their habitats
If the disease is confirmed in a wild population the outbreak will be controlled in line with the contingency plan for exotic notifiable diseases.
Further information on Bsal
For further information on prevention and control, see the:
- Garden Wildlife Health (GWH) scheme Amphibian Disease Alert
- guidelines for safe disposal of wastewater and other materials from captive amphibian enclosures
For further information on the import of live amphibians of the order Caudata (salamanders and newts), read the guidance on quarantine requirements for live amphibians of the order Caudata (salamanders and newts)
Legislation relating to Bsal
The main legislation relating to Bsal includes the:
- Animal Health Act 1981
- Specified Diseases (Notification and Control) (Amendment, etc.) (England) Order 2021 (SI 2021/443)
- Commission Implementing Decision (EU) Decision 2018/320 (from 28 February 2018 amended and retained in UK legislation under The Import of, and Trade in, Animals and Animal Products (Miscellaneous Amendments) (EU Exit) Regulations 2020 SI 2020/1462)