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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #308070
Title: Efficacy of florfenicol for control of mortality associated with Edwardsiella ictaluri in three species of catfish

Author
item GAUNT, PATRICIA - Mississippi State University
item Chatakondi, Nagaraj
item GAO, DANA - Mississippi State University
item ENDRIS, RICHARD - Merck Animal Health

Submitted to: Journal of Aquatic Animal Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/13/2014
Publication Date: 2/23/2015
Citation: Gaunt, P.S., Chatakondi, N.G., Gao, D., Endris, R. 2015. Efficacy of florfenicol for control of mortality associated with Edwardsiella ictaluri in three species of catfish. Journal of Aquatic Animal Health. 27:45-49.

Interpretive Summary: Enteric Septicemia of Catfish caused by Edwardseilla ictaluri is a prevalent bacterial infection affecting US farm raised catfish. Channel catfish and hybrid catfish in production ponds are equally effected by this disease. Antibiotics and feed management are effective ways to combat the problem. The efficacy of florfenicol (FFC) medicated feed to reduce the mortalities associated with ESC among channel catfish, blue catfish and hybrid fingerlings was assessed in either 0 or 10 mg florfenicol medicated feed in replicated aquaria under standard laboratory conditions. The mean cumulative percent of mortalities in the non-midicated feed did not differ between blue ( 38%), hybrid (40%) and channel (48%) catfish. However, post-disease challenge treatment with florfenicol medicated feed sign This study provides an effective strategy to combat the prevailing ESC disease in channel, blue and hybrid catfish. Reduced losses (30 to 75%) improve the profitability and decreased cost of production.

Technical Abstract: The efficacy of florfenicol against Edwardsiella icatluri infection was studied in channel catfish (Ictalurus puntatus (Delta strain)), hybrid catfish (Ictalurus punctatus (Delta strain) x Ictalurus furcatus (D&B strain)), and blue catfish (Ictalurus furcatus (D&B strain) fingerlings in 65L aquaria. Fish were challenged by immersion on Day 0. For each of the three species of catfish, ten 65 liter tanks were randomly assigned in equal number to two treatment groups, either treated with 0- mg florfenicol / kg body weight (unmedicated feed) or 10- mg florfenicol /kg body weight in medicated feed for ten consecutive days. Mortality was monitored during the 10-d treatment period and during a 14-d post-treatment observation period. At the end of the 14-d post-treatment observation period, all fish were euthanized, examined for gross lesions, and cultured for E. ictaluri. The mean cumulative percent mortality to enteric septicemia of catfish challenge among the three genotypes of catfish did not differ between blue (38%), hybrid (40%), and channel (48%) catfish. However, post- disease challenge, treatment with florfenicol medicated feed significantly decreased mortality (6%) compared to control treatment (78%). All genotypes of catfish tested were responsive to treatment with florfenicol medicated feed for control of mortality associated with ESC. There were no significant differences in mortality associated with hybrid catfish (Delta x blue), blue catfish, and channel catfish (Delta pool).