Test the efficacy and safety of substance x (effect through bath) and y ,z (safety through feed) intended to be used against parasites A and B respectively in Atlantic salmon (Salmo salar)

Parasite A causes serious losses to the salmon farming industry and several methods have been employed (both physical and chemical) to reduce its effect on farmed salmon. Some of the chemicals already in use have become ineffective due to development of resistance. Substance x is a chemical that showed promising results in vitro and earlier in vivo studies against parasite A but the efficacy at much lower doses have to be demonstrated through further fish trials. Substances y,z (against parasite B) have been found to be effective invitro, but their safety for fish has to be established in a controlled study through their intended mode of administration (feed). The effect of infection with parasite A could be be classified as moderately severe and the safety experiments where the effect of chemicals on salmon has not yet been documented, the highest degree of severity is considered as an outcome. A total of 276 Atlantic salmon will be used in the study. This will include parrs (safety study) and smolts (efficacy study). There are no alternatives to the safety and efficacy testing on fish at present but the number of fish has been reduced due to the use of invitro testing directly on the parasites. Fish will be accommodated in a favourable light regime and water quality will be monitored. Humane endpoint will be implemented.