Radiological detection of nephrocalcinosis in farmed Atlantic salmon Salmo salar L.
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https://hdl.handle.net/10037/27307Date
2022-08-14Type
Journal articleTidsskriftartikkel
Peer reviewed
Author
Klykken, Christine; Dalum, Alf Seljenes; Reed, Anne Katrine; Attramadal, Kari; Olsen, Rolf Erik; Boissonnot, Lauris Jeannine ErnestineAbstract
Nephrocalcinosis is a common disorder in nurseries in Norway
(Klykken, Reed, et al., 2022) and was reported as one of the main
welfare challenges in farmed salmon by The Norwegian Fish Health
Report of 2019 (Sommerset et al., 2020).
Nephrocalcinosis is described as deposits of minerals within the
kidneys (Bruno, 1996), that can disturb kidney function, which in
turn can have dramatic consequences on fish performance and survival. The aetiology is most likely related to environmental factors,
and suboptimal water quality has been indicated in several studies
as the main risk factor (Fivelstad et al., 1999; Fivelstad et al., 2003;
Khan et al., 2018; Fivelstad et al., 2015; Good et al., 2010; Lewisch
et al., 2013; Chen et al., 2001). Newly conducted research suggested
that osmoregulatory stress may be the trigger for nephrocalcinosis
(Boissonnot et al., 2022).
Regardless of the severity of the condition, fish rarely present
external signs, and it is thus challenging to monitor its prevalence
and development. Present diagnostic methods require euthanasia as
they consist of visually scoring the accumulation of deposits and the
severity of lesions. Macroscopic assessments of necropsied fish are
often imprecise, since small deposits are rarely visible to the naked
eye, and histopathology is therefore considered as the best existing
diagnostic method (Klykken, Boissonnot, et al., 2022). Research on,
and monitoring of, nephrocalcinosis has been greatly hampered by
the lack of non-invasive methods of assessing the presence and
severity of this condition, as it is not possible to follow the development of the disease in single individuals, and as the number of
sampled fish is limited due to ethical reasons.
Radiology has previously been used for assessing vertebrae deformities in Atlantic salmon (Drábiková et al., 2021; Holm
et al., 2020), based on the classification scheme developed by
Witten et al. (2009), and there has been a rapid development of
the technology (Ou et al., 2021) including portable systems, which
allow efficient in situ diagnosis. Nephrocalcinosis in Atlantic salmon
is mainly identified as amorphous carbonate apatite, a calciumdominated mineral (Klykken, Reed, et al., 2022), and it has previously
been demonstrated that this mineral composition is suitable for xray detection (Smith & Lehr, 1966). Radiology is non-invasive and can
be performed on anaesthetized fish, enabling assessment of nephrocalcinosis without euthanazing the fish. A non-invasive method for
assessing nephrocalcinosis would allow for monitoring of the condition over time on an individual level and would be ethically and
economically preferable. We have therefore explored radiology as a
possible tool to detect and evaluate the severity of nephrocalcinosis,
comparing it with histological scoring.
Publisher
WileyCitation
Klykken, Dalum, Reed, Attramadal, Olsen, Boissonnot. Radiological detection of nephrocalcinosis in farmed Atlantic salmon Salmo salar L.. Journal of Fish Diseases. 2022Metadata
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