A study on the efficacy of cypermethrin and deltamethrin on resistant sea lice (copy)
This application was submitted and approved in 2015 for the period 02.11.2015-03.01.2016, but due to delays we were not able to conduct the experiment within this time frame. Unfortunately we did a mistake when setting the application period for the exact time span for when we planned to do the experiment, and not for four years as we could have done. Since it was not possible do extend the application period we therefore re-submit the application aiming to carry out the experiment this fall:
Adaptation of sea lice to the use of pyrethroids has led to recognized resistant strains (Aaen et al 2015) and as a result there is anecdotal use of products ‘off label’ using longer exposure times or higher doses to overcome resistant lice infestation. Betamax vet (Elanco Animal Health, contains cypermethrin) and Alphamax/AMX (Pharmaq AS, contains deltamethrin) are licensed veterinary medicines in Norway for the treatment and control of adult and pre-adult stages of sea lice This study is designed to examine the efficacy of these available agents when used against LsH2O2 sea lice that have recognized characteristics of resistance against pyrethroids. The aim of this study is:
1) To compare the efficacy of cypermethrin or delatmethrin against LsH2O2 sea lice hosted on Atlantic salmon.
2. To compare the efficacy of cypermethrin or delatmethrin administered at double the standard treatment time at the standard dose or at double the standard dose against infestations of LsH202 sea lice.
The candidates will be administered as bath treatment in single fish tanks with Atlantic salmon (Salmo salar) infected with sea lice (Lepeophtheirus salmonis). Following administration of drugs the loss of lice will be monitored for a week in order to evaluate drug efficacy.
Adaptation of sea lice to the use of pyrethroids has led to recognized resistant strains (Aaen et al 2015) and as a result there is anecdotal use of products ‘off label’ using longer exposure times or higher doses to overcome resistant lice infestation. Betamax vet (Elanco Animal Health, contains cypermethrin) and Alphamax/AMX (Pharmaq AS, contains deltamethrin) are licensed veterinary medicines in Norway for the treatment and control of adult and pre-adult stages of sea lice This study is designed to examine the efficacy of these available agents when used against LsH2O2 sea lice that have recognized characteristics of resistance against pyrethroids. The aim of this study is:
1) To compare the efficacy of cypermethrin or delatmethrin against LsH2O2 sea lice hosted on Atlantic salmon.
2. To compare the efficacy of cypermethrin or delatmethrin administered at double the standard treatment time at the standard dose or at double the standard dose against infestations of LsH202 sea lice.
The candidates will be administered as bath treatment in single fish tanks with Atlantic salmon (Salmo salar) infected with sea lice (Lepeophtheirus salmonis). Following administration of drugs the loss of lice will be monitored for a week in order to evaluate drug efficacy.