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Fenicyl (Canada)

This page contains information on Fenicyl for veterinary use.
The information provided typically includes the following:
  • Fenicyl Indications
  • Warnings and cautions for Fenicyl
  • Direction and dosage information for Fenicyl


This treatment applies to the following species:
Company: Vetoquinol

Florfenicol 300 mg/mL


DIN 02497166

Sterile Injectable Antibiotic Solution

For Intramuscular and Subcutaneous use in Beef and Non-lactating Dairy Cattle only.


Fenicyl is a light yellow to straw coloured, slightly viscous solution. Each millilitre contains; Active ingredient: 300 mg florfenicol; Inactive ingredients: 250 mg 2-pyrrolidone, formal glycerol q.s. to 1.0 mL.

Fenicyl Indications

Fenicyl Injectable Solution is indicated for the treatment of bovine respiratory disease complex, also called shipping fever, associated with Mannheimia haemolytica, Pasteurella multocida and Histophilus somni (Haemophilus somnus) and for the reduction of morbidity associated with bovine respiratory disease (BRD) in feedlot calves, caused by Mannheimia haemolytica, Pasteurella multocida and Histophilus somni (Haemophilus somnus), during the first 28 days in the feedlot, when administered at the time of arrival. Also for the treatment of bovine interdigital phlegmon (foot rot, interdigital necrobacillosis, infectious pododermatitis) associated with Fusobacterium necrophorum and Bacteroides melaninogenicus and for the treatment of infectious bovine keratoconjunctivitis (IBK, Pinkeye) caused by Moraxella bovis.

Dosage and Administration

Fenicyl Injectable Solution should be administered to cattle either by a single subcutaneous injection at a dose rate of 40 mg/kg body weight (6 mL/45 kg); or by intramuscular injection at a dose of 20 mg/kg body weight (3 mL/45 kg), a total of two doses with a 48 hour interval should be given. For feedlot calves at high risk of developing BRD, only the subcutaneous route (SC) of administration (40 mg/kg, once on arrival in the feedlot) is recommended. Do not inject more than 10 mL into a single site.

On Arrival Treatment:

Note: To limit the development of antimicrobial resistance, Fenicyl should only be used as an arrival treatment when: 1) BRD has been diagnosed; and 2)  calves are at “high risk” of developing BRD. One or more of the following factors typically characterizes calves at “high risk” of developing BRD. Calves are from multiple farm origins, and/or calves have extended transport times (that may have included few if any rest stops), and/or ambient temperature change(s) from origin to arrival of 17°C or more, and/or animals have had continuous exposure to extremely wet and cold weather conditions, and/or calves have experienced excessive shrink or stressful processing procedures, such as castration or dehorning.

Clinical improvement should be evident in most treated subjects within 24 hours of initiation of treatment. If a positive response is not noted within 72 hours of initiation of treatment, the diagnosis should be reevaluated.

Fenicyl Caution

Transient diarrhea or transient inappetence may occur with the use of this drug. Appetite and stool will usually return to normal within a few days of the end of the treatment period.

Not for use in breeding cattle. The effects of florfenicol on bovine reproductive performance, pregnancy and lactation have not been assessed. DO NOT USE IN SWINE.


Treated cattle must not be slaughtered for use in food for at least 36 days after the latest intramuscular treatment or at least 55 days after the latest subcutaneous treatment with this drug.

Do not use in dairy cows 20 months of age or older.

Do not use in calves to be processed for veal. A withdrawal period has not been established in pre-ruminating calves.

Do not use in swine.

This product contains materials that can be irritating to skin and eyes. Avoid direct contact with skin or eyes. In case of accidental eye exposure, flush with water for 15 minutes. In case of accidental skin exposure, wash with soap and water. Remove contaminated clothing. Consult a physician if irritation persists. Accidental injection of this product may cause local irritation. Consult a physician immediately.

To limit the development of antimicrobial resistance, Fenicyl should only be used as an arrival treatment in feedlot calves when BRD has been diagnosed and calves are at high risk of developing BRD.

Keep out of the reach of children.

Adverse Reactions

Transient inappetence, decreased water consumption, or diarrhea have been reported very rarely following treatment. Anaphylactic / allergic-type reactions have been reported very rarely and may require treatment.

Clinical Pharmacology

Florfenicol is a synthetic, broad spectrum antibiotic. In vitro and in vivo activity has been demonstrated against the most commonly isolated bacterial pathogens involved in bovine shipping fever including Mannheimia haemolytica, Pasteurella multocida and Histophilus somni (Haemophilus somnus). Also effective in vivo against other bacteria like; Fusobacterium necrophorum, Bacteroides melaninogenicus, both bacteria associated with foot rot, and Moraxella bovis associated with pinkeye.

Florfenicol has also shown significant in vitro activity against the following gram negative pathogens of animals; Escherichia coli, Salmonella spp. and Klebsiella spp. Gram positive activity was shown in vitro against Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Streptococcus bovis, Streptococcus zooepidemicus, Streptococcus suis, Staphylococcus aureus, Staphylococcus intermedius and Staphylococcus epidermidis. In vitro activity against Mycoplasma hyopneumonia and Mycoplasma hyorhinis has also been detected. However, the clinical significance of this activity in cattle is not known.

The pharmacokinetic profile of florfenicol was evaluated in cattle using single intravenous and intramuscular administration at the recommended dose of 20 mg/kg. Intravenous administration of florfenicol resulted in a mean peak serum concentration of 44.56 µg/mL five minutes after dosing and a mean serum concentration of 0.91 µg/mL twelve hours after dosing. The harmonic mean elimination half-life was 154 minutes and the median volume of distribution at steady state (Vdss) was 0.77 L/kg indicating excellent penetration of florfenicol into body tissues and fluids. The median area under the concentration vs time curve (AUCo∞) was 5403 µg/mL x minutes. Intramuscular administration of florfenicol using the same dose resulted in a maximum mean serum concentration (Cmax) of 3.21 µg/mL which occurred 200 minutes (Tmax) after dosing. The mean concentration 24 hours after dosing was 0.77 µg/mL. Florfenicol was detectable in the serum of most animals through 60 hours after dosing with a mean concentration of 0.19 µg/mL. The median AUCo∞ was 4242 µg/mL x minutes and the median bioavailability was 79.8%.

STORAGE CONDITIONS: Store at or below 25°C (77°F). The solution is light yellow to straw colored. Use within 28 days of first vial puncture.

How Supplied

Fenicyl Injectable Solution is packaged in 100 mL, 250 mL and 500 mL multiple dose plastic vials.

Manufactured by:

Norbrook Laboratories Limited, Newry, BT35 6PU, Co. Down, Northern Ireland.

Distributed by:

Vetoquinol N.-A. Inc., 2000, ch. Georges, Lavaltrie, QC, Canada, J5T 3S5

Revision date March 2020




100 mL





250 mL



500 mL



CPN: 1234473.0

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