Use of a potentiated sulfonamide to control Edwardsiella ictaluri infection in channel catfish ( Ictalurus punctatus)

Abstract

The effective level of a potentiated sulfonamide (Romet-30 ™) was determined in two laboratory trials in channel catfish ( Ictalurus punctatus) experimentally infected with Edwardsiella ictaluri. Romet reduced the average mortality from 60% in the infected-unmedicated fish to 38% for 25 mg/kg, 32% for 50 mg/kg and 24% for 75 mg/kg of fish in the infected-medicated groups. In four field trials conducted with fish experimentally infected with E. ictaluri, the 50 mg/kg dose significantly ( P < 0.05) reduced the mortality from 25.8% in the infected-unmedicated fish to 10.5% in the infected-medicated groups. E. ictaluri was isolated from moribund fish in both medicated and unmedicated groups.