Ulcerative dermal necrosis (UDN), a chronic skin condition, affects primarily mature wild salmonids returning from the sea to freshwater for their spawning. The involvement of water moulds such as Saprolegnia parasitica as a secondary pathogen in this disease is clear but the identification of a primary cause or of primary pathogen(s) remains elusive. In this opinion article, we re-visit UDN regarding epidemiology, pathology and aetiology and speculate the potential involvement of UV radiation in the initiation of UDN in salmonid fish returning from the sea.
Bibliographical noteFunding Information:
This work was partially funded from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska–Curie grant agreement No 766048 (PROTECTA).
- Atlantic salmon
- Saprolegnia parasitica
- Skin damage
- Stress factor
- Ulcerative dermal necrosis
- Ultraviolet radiation