Forsøksdyr: Test the efficacy of compounds v,w and x against pathogen L in Atlantic salmon

Godkjenningsdato 09.10.2020

Godkjenningsperiode 09.10.2020-01.10.2022

1 Formål
The objective of the trial is to document the efficacy and pharmacokinetics of selected compounds against pathogen L in Atlantic salmon. The administration of study compounds are planned as in-feed or bath.
2 Skadevirkninger
The experiment will be classified as moderately stressful overall as the study involves infestation with a restricted number of pathogen L over a maximum of 8 weeks which can be considered moderately stressful (mild stress over a long period as per forsøksdyrforskriften Vedlegg B Del 1). Additionally, the compounds tested here and their family chemicals have already been tested in salmon through bath and feed and did not elicit any safety concerns. This means that the experiment should be classified as moderately stressful.

3 Forventet nytteverdi
Pathogen L is a persistent threat to the salmon farming sector and results in large scale economic losses. Additionally, animal welfare is also compromised when pathogen number exceed a certain limit. It is expected that, if found promising in this study, these test compounds could be further developed as potential therapeutic agents against pathogen L.
4 Antall dyr og art
370 Atlantic salmon smolts will be used in this study for either in-feed or bath treatment
5 Hvordan etterleve 3R
ERSTATNING: An effect study on live fish needs to be done because the pathogen L can behave or respond differently when attached to fish as opposed to an invitro experiment where they are deprived from their natural host and source of feed/ nutrition.

REDUKSJON: Total fish numbers are calculated based on approximate fish numbers of about 5-10 fish required per sampling. The objective of the experiment is to identify near to 100% efficacy dose and therefore a sample size based on statistical method has not been used. The fish numbers are considered enough based on previous experiments with same compounds (FOTS ID 19121, 20893)

FORBEDRING: Fish used in the study will be vaccinated against relevant opportunistic infections that arise primarily due to handling. Additionally, fish will be euthanized by anesthetic overdose for sampling . Fish will be handled gently according to internal SOPs at NIVA Solbergstrand. Use of humane endpoint (euthanizing of moribund fish) will reduce the suffering for individual fish if some adverse effect of challenge or treatment surfaces.