Code of Federal Regulations (alpha)

CFR /  Title 21  /  Part 558  /  Sec. 558.261 Florfenicol.

(a) Specifications. Type A medicated articles containing florfenicol in the following concentrations:

(1) 40 grams per kilogram for use as in paragraph (e)(1) of this section.

(2) 500 grams per kilogram for use as in paragraph (e)(2) of this section.

(b) Sponsor. See No. 000061 in Sec. 510.600(c) of this chapter.

(c) Special considerations--(1) Federal law limits this drug to use under the professional supervision of a licensed veterinarian. See Sec. 558.6 of this chapter for additional requirements.

(1) Federal law limits this drug to use under the professional supervision of a licensed veterinarian. See Sec. 558.6 of this chapter for additional requirements.

(2) The expiration date of veterinary feed directives (VFDs) for florfenicol medicated feeds:

(i) For freshwater-reared finfish, must not exceed 15 days from the date of issuance.

(ii) For swine must not exceed 90 days from the date of issuance.

(3) VFDs for florfenicol shall not be refilled.

(d) Related tolerances. See Sec. 556.283 of this chapter.

(e) Conditions of use--(1) Swine-- ------------------------------------------------------------------------

Florfenicol in grams/ton of

feed Indications for use Limitations------------------------------------------------------------------------182......................... For the control of Feed continuously as

swine respiratory a sole ration for 5

disease (SRD) consecutive days.

associated with The safety of

Actinobacillus florfenicol on

pleuropneumoniae, swine reproductive

Pasteurella performance,

multocida, pregnancy, and

Streptococcus suis, lactation have not

and Bordetella been determined.

bronchiseptica in Feeds containing

groups of swine in florfenicol must be

buildings withdrawn 13 days

experiencing an prior to slaughter.

outbreak of SRD..------------------------------------------------------------------------

(2) Fish-- ------------------------------------------------------------------------

Florfenicol in grams/ton of

(i) 182 to 2,724............ Catfish: For the Feed as a sole

control of ration for 10

mortality due to consecutive days to

enteric septicemia deliver 10 to 15

of catfish milligrams (mg)

associated with florfenicol per

Edwardsiella kilogram (kg) of

ictaluri. fish. Feed

containing

florfenicol shall

not be fed for more

than 10 days.

Following

administration,

fish should be

reevaluated by a

licensed

veterinarian before

initiating a

further course of

therapy. A dose-

related decrease in

hematopoietic/

lymphopoietic

tissue may occur.

The time required

for hematopoietic/

lymphopoietic

tissues to

regenerate was not

evaluated. The

effects of

florfenicol on

reproductive

performance have

not been

determined. Feeds

containing

florfenicol must be

withdrawn 15 days

prior to slaughter.------------------------------------------------------------------------

(ii) 182 to 1,816........... Freshwater-reared Feed as a sole

salmonids: For the ration for 10

control of consecutive days to

mortality due to deliver 10 to 15 mg

coldwater disease florfenicol per kg

associated with of fish. Feed

Flavobacterium containing

psychrophilum and florfenicol shall

furunculosis not be fed for more

associated with than 10 days.

Aeromonas Following

salmonicida. administration,

fish should be

reevaluated by a

licensed

veterinarian before

initiating a

further course of

therapy. The

effects of

florfenicol on

reproductive

performance have

not been

determined. Feeds

containing

florfenicol must be

withdrawn 15 days

prior to slaughter.------------------------------------------------------------------------(iii) 182 to 2,724.......... Freshwater-reared Feed as a sole

finfish: For the ration for 10

control of consecutive days to

mortality due to deliver 10 to 15 mg

columnaris disease florfenicol per kg

associated with of fish for

Flavobacterium freshwater-reared

columnare. warmwater finfish

and other

freshwater-reared

finfish. Feed

containing

florfenicol shall

not be fed for more

than 10 days.

Following

administration,

fish should be

reevaluated by a

licensed

veterinarian before

initiating a

further course of

therapy. For

catfish, a dose-

related decrease in

hematopoietic/

lymphopoietic

tissue may occur.

The time required

for hematopoietic/

lymphopoietic

tissues to

regenerate was not

evaluated. The

effects of

florfenicol on

reproductive

performance have

not been

determined. Feeds

containing

florfenicol must be

withdrawn 15 days

prior to slaughter.------------------------------------------------------------------------(iv) 273 to 2,724........... Freshwater-reared Feed as a sole

warmwater finfish: ration for 10

For the control of consecutive days to

mortality due to deliver 15 mg

streptococcal florfenicol per kg

septicemia of fish. Feed

associated with containing

Streptococcus iniae. florfenicol shall

not be fed for more

than 10 days.

Following

administration,

fish should be

reevaluated by a

licensed

veterinarian before

initiating a

further course of

therapy. For

catfish, a dose-

related decrease in

hematopoietic/

lymphopoietic

tissue may occur.

The time required

for hematopoietic/

lymphopoietic

tissues to

regenerate was not

evaluated. The

effects of

florfenicol on

reproductive

performance have

not been

determined. Feeds

containing

florfenicol must be

withdrawn 15 days

prior to slaughter.------------------------------------------------------------------------ [70 FR 70047, Nov. 21, 2005, as amended at 71 FR 70304, Dec. 4, 2006; 72 FR 19798, Apr. 20, 2007; 72 FR 65885, Nov. 26, 2007; 77 FR 32012, May 31, 2012; 79 FR 18159, Apr. 1, 2014]