Drug Summary & History
Florfenicol INAD 10-697

Florfenicol is a potent, broad-spectrum, antibacterial agent with bacteriostatic properties. Florfenicol, when administered to fish in feed, has been used to control mortality in (a) Atlantic salmon Salmo salar diagnosed with furunculosis, (b) yellowtail (buri) Seriola quinqueradiate diagnosed with pseudotuberculosis, (c) goldfish Carassius auratus diagnosed with vibrosis, and (d) Japanese eel Anguilla japnica infected with Edwardsiella tarda. Pivotal and supportive INAD trials have shown that florfenicol is also effective in controlling mortality in a variety of freshwater reared salmonids caused by coldwater disease, furunculosis, and columnaris, and mortality in hybrid striped bass caused by strep. Aquaflor® is a florfenicol-based premix developed for aquaculture, and it is approved in Canada to control mortality in Atlantic salmon diagnosed with furunculosis.

The primary goal of field studies conducted under INAD #10-697 is to evaluate the efficacy of florfenicol-medicated feed for controlling mortality in a variety of fish species diagnosed with a variety of diseases that are caused by pathogens susceptible to florfenicol. For example, diseases of interest include, but are not limited to, (a) coldwater disease, (b) columnaris, (c) furunculosis, (d) enteric septicemia in catfish, (e) enteric redmouth, (f) bacterial hemorrhagic septicemia caused by Aeromonads and Pseudomonads, and (g) streptococcal infection. Under this INAD, Schering-Plough Animal Health (Union, NJ) is the only authorized supplier of florfenicol (packaged as Aquaflor® premix) to all Investigators. One treatment option is allowed (administer Aquaflor® in feed at 10 mg active florfenicol/kg fish/day for 10 consecutive days), and the withdrawal period for salmonids and non-salmonids is 21 and 28 d, respectively.