DAO 70:109-114 (2006)  -  doi:10.3354/dao070109

Historical control clinical trial to assess the effectiveness of teflubenzuron for treating sea lice on Atlantic salmon

P. J. Campbell1,3, K. L. Hammell1,*, I. R. Dohoo1, G. Ritchie2

1Department of Health Management, Atlantic Veterinary College, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3, Canada
2Nutreco Aquaculture Research Centre, PO Box 48, Sjohagen 3, 4001 Stavanger, Norway
3Present address: Inwood Animal Center, 7611 Winchester Avenue, Inwood, West Virginia 25428, USA
*Corresponding author. Email:

ABSTRACT: A historical control clinical trial was performed to assess the effectiveness of teflubenzuron in controlling sea lice Lepeoptheirus salmonis burdens on farmed Atlantic salmon Salmo salar over time. The study site comprised 9 sea cages, all of which were treated. The teflubenzuron was administered in the feed, at a dosage of 10 mg kg–1 biomass d–1, over a treatment period of 7 d. At 1 wk post-treatment, sea lice chalimus and mobile stages were reduced by 92 and 74% (both p < 0.001), respectively. At 2 wk post-treatment, chalimus stages were reduced by 41% and mobile stages 61% (both p < 0.001) compared to pre-treatment levels. At 3 wk post-treatment, chalimus stages were still 36% (p < 0.001) lower than pre-treatment levels, but mobile stages had increased to above pre-treatment levels. Our results show that the effects of teflubenzuron are limited to a 3 wk duration, but that with appropriate management, farms could benefit from these reduced lice burdens for longer periods.


KEY WORDS: Sea lice · Lepeoptheirus salmonis · Teflubenzuron · Atlantic salmon · Salmo salar · Clinical trial


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