Disease: Ranavirus

This page provides general information about this condition. Text can be revealed by clicking on the green headers. Links to press releases, results from DWHC investigations as well as other useful documents and relevant literature available on the DWHC website can be found at the bottom of the page.

In 2010, ranavirus was found for the first time in the Netherlands when a volunteer from the Dutch amphibian, reptile and fish research organisation discovered thousands of dead frogs in the Dwingelderveld National Park. Investigations carried out by the DWHC showed ranavirus to be the cause of death.


Ranavirus is a member of the Iridoviridae family of viruses. The genus contains several sorts of ranavirus including the Common Midwife Toad Virus (CMTV); this and the CMTV-like forms have been detected in the Netherlands.

Susceptible species

Ranaviruses occur in amphibians, reptiles and fish. In the Netherlands, ranavirus has been found in all three native sorts of water frogs (the pool frog, lake frog and common water or green frog) as well as in the European common frog, common toad, spadefoot toad, common (smooth) newt and the great crested newt. In other countries ranavirus has also been found in fire salamanders, alpine salamanders and common midwife toads.

Signs in animals

The lesions associated with ranavirus infection are skin ulceration and haemorrhages in the skin and internal organs. These lesions are, however, not unique to ranavirus and furthermore, are not seen in every case of ranavirus infection.

Infection of animals

Ranavirus is spread via direct or indirect contact. For example ingestion of an infected animal or skin-skin contact constitute direct pathways; importantly skin damage is not necessary for infection to occur. Indirect contact could involve contact with contaminated water and sediment or materials such as boots, buckets and machinery used by researchers or people working on the waterways.

Geographical distribution

In the Netherlands, ranavirus has been found in provinces throughout the country: Friesland, Drenthe, Overijssel, Gelderland, Noord-Brabant en Limburg.

Preventative measures

To avoid spreading the disease frogs and newts should not be relocated or released in the wild. The virus survives in soil and mud and it is, therefore, important that all equipment used in canals and ponds should be scrubbed to remove remnants of soil and then rinsed with soap and clean water. These measures can remove pathogens minimizing the chance of spread between areas.  Field-researchers should, where possible, work in the direction of the current so as not to spread infection upstream. The relocation of water-plants, fish and amphibians should be avoided.

External information


Research results



  • The Fourth International Symposium on Ranaviruses: Summary of North American Herpetological Content and Points of Interest. Ash L., R. Marschang, J. Rijks & A. Duffus. (2020). Journal of North American Herpetology, 1, p. 29-31. doi: 10.17161/jnah.vi.13539
  • Ranavirus genotypes in the Netherlands and their potential association with virulence in water frogs (Pelophylax spp.). Saucedo B., J. Hughes, A. Spitzen-van der Sluijs, N. Kruithof, M. Schills, J.M. Rijks, M. Jacinto-Maldonado, N. Suarez, O.L.M. Haenen, M. Voorbergen-Laarman, J. van den Broek, M. Gilbert, A. Gröne, S.J. van Beurden & M.H. Verheije (2018). Emerg Microbes Infect. 2018 Apr 4;7(1):56. doi: 10.1038/s41426-018-0058-5
  • Monitoring Ranavirus-Associated Mortality in a Dutch Heathland in the Aftermath of a Ranavirus Disease Outbreak. Sluijs A.S., J. van den Broek, M. Kik, A. Martel, J. Janse, F. van Asten, F. Pasmans, A. Gröne & J.M. Rijks. J Wildl Dis. 2016 Jul 25. [Epub ahead of print]. DOI: 10.7589/2015-04-104
  • Investigation of Amphibian Mortality Events in Wildlife Reveals an On-Going Ranavirus Epidemic in the North of the Netherlands. Rijks JM, Saucedo B, Spitzen-van der Sluijs A, Wilkie GS, van Asten AJAM, van den Broek J, et al (2016). PLoS ONE 11(6): e0157473. doi:10.1371/journal.pone.0157473
  • Ranavirus-associated mass mortality in wild amphibians, The Netherlands, 2010: A first report. Kik M, Martel A, Spitzen-van der Sluijs A, Pasmans F, Wohlsein P, Gröne A & Rijks JM (2011). The Veterinary Journal, 2011, 190: 284–286 Klik hier voor meer informatie