Drug profile

The FDA adverse-event record for Florfenicol

303 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Florfenicol. See the species affected, top reactions, and outcomes below.

303
adverse-event reports
44.6%
death-coded share
Cattle
most-reported species
101
Death - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
303
Total Reports
135
Deaths Reported
44.6%
Death Rate

Active Ingredients

Florfenicol

Administration Routes

UnknownSubcutaneousOralIntramuscularTopicalParenteralOphthalmicNasalOtherIntraocular

Species Affected

Cattle 130
Unknown 72
Fish 34
Human 32
Goat 10
Dog 7
Pig 6
Sheep 6
Cat 4
Alpaca 1

Most Affected Breeds

Unknown 120
Crossbred Bovine/Cattle 39
Cattle (unknown) 25
Holstein-Friesian also known as Holstein 22
Fish (unknown) 16
Aberdeen Angus 14
Cattle (other) 14
Mixed (Cattle) 11
Goat (unknown) 5
Sheep (unknown) 4

Most Reported Reactions

Death 101
Lack of efficacy (bacteria) - NOS 62
Unclassifiable adverse event 42
Accidental exposure 25
Lack of efficacy - NOS 18
Vials, Leaking 15
Respiratory tract disorder NOS 14
Injection site pain 13
Death by euthanasia 13
Skin lesion NOS 12
Injection site swelling 11
Necropsy performed 11

Outcome Breakdown

Died
126 (59.4%)
Recovered/Normal
31 (14.6%)
Outcome Unknown
30 (14.2%)
Euthanized
13 (6.1%)
Ongoing
11 (5.2%)
Recovered with Sequela
1 (0.5%)

Florfenicol Adverse Event Insights

303 reports name Florfenicol; 135 recorded a death outcome (44.6% of reported events, not a population-level mortality rate). Active ingredient: Florfenicol. Administration routes: Unknown, Subcutaneous, Oral, Intramuscular.

By species: Cattle (130 reports), Unknown (72 reports), Fish (34 reports). By breed: Unknown (120), Crossbred Bovine/Cattle (39), Cattle (unknown) (25).

Leading clinical signs: Death (101), Lack of efficacy (bacteria) - NOS (62), Unclassifiable adverse event (42), Accidental exposure (25). Outcome, 212 coded reports: Died leads at 59.4%.

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.