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

Godkjenningsdato 16.09.2020

Godkjenningsperiode 01.10.2020-01.08.2022

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 bath.

2 Skadevirkninger
The experiment will be classified as moderate overall as the study involves infestation with a restricted number of pathogen L over a maximum of 4 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 have been administered through bath before on the target animal and therefore safety of these compounds have been already established.

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
450 Atlantic salmon smolts will be used in this study.

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 will be euthanized by anesthetic overdose for sampling. Fish will be handled gently according to internal SOPs at ILAB. Use of humane endpoint (euthanizing of moribund fish) will reduce the suffering for individual fish if some adverse effect of challenge or treatment surfaces.