DAO 67:87-92 (2005)  -  doi:10.3354/dao067087

ABSTRACT: The efficacy of orally administered flumequine in the treatment of experimentally induced vibriosis in Atlantic cod Gadus morhua was investigated. Cod (mean ± SD, 120 ± 30 g) were randomly distributed to twelve tanks and bath challenged for 1 h with Listonella anguillarum serotype O2α, strain HI-610, using a dose of 9.2 × 10⁶ CFU ml^–1. At 3 d post-challenge, medication was introduced in 10 of the groups at doses of 2.5, 5, 10, 15 and 25 mg flumequine kg^–1 body weight d^–1 in duplicate. The medication was administered on Days 1, 2, 4, 6, 8, and 10 after the initiation of treatment. In challenged unmedicated fish, mortality started on Day 4 post-challenge, reaching a final cumulative mortality of 82% at Day 18. In the medicated groups, mortality started on Days 3 to 5 post-challenge, reaching final cumulative mortalities of 42, 49, 37, 37 and 23% respectively for the fish treated with 2.5, 5, 10, 15 and 25 mg flumequine kg^–1 body weight d^–1. Survival of medicated fish in all groups was significantly greater than in challenged unmedicated fish (p < 0.001). Twenty-four h following the final medication, HPLC analysis found a linear relationship between doses and mean concentrations of the drug in plasma, muscle and liver.

KEY WORDS: Efficacy · Flumequine · Gadus morhua · Vibriosis · Listonella anguillarum