Drug profile

The FDA adverse-event record for Florfenicol

317 FDA reports name Florfenicol, a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#400 of 2,679
by report volume (all drugs)
317
adverse-event reports
45.7%
death-coded share
Cattle
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Florfenicol ranks #400 of 2679 by total reports (317) and #72 of 1130 by death-coded share (45.7%). National dual: Milbemycin Oxime + Spinosad is #1 of 2679 drugs by total adverse-event reports (149,624) at death-coded-share rank 965 of 1130 drugs with at least 50 reports (2.3%); separately, Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) is #1 highest death-coded share at 97.8% (report rank #821).

149,624
Milbemycin Oxime + Spinosad reports (#1)
97.8%
Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) death share (#1)
#400
This drug, reports of 2679
#72
This drug, death share of 1130

Report volume reflects how common a breed or drug is and how often owners and vets file — not actual risk. Death-coded share ranks are limited to entries with enough reports to be meaningful. The two maps do not agree at #1.

Release-over-release change

What changed in the latest FDA data snapshot

PlainBreed reconstructed the prior snapshot from dated openFDA partitions through 2025 Q4, then compared it with the 2026-07-27 openFDA export. Florfenicol has 317 reports now versus 316 in that prior snapshot: 1 more (0.3%).

Report change
+1
Death-coded reports
+1
Death-coded share
+0.2 pts

This compares reported-event counts in two source snapshots. It does not establish a change in real-world risk, product safety, or disease incidence.

Subscribe to Florfenicol changes

Signature read: death-coded report count at 145 is the most distinctive stamp on Florfenicol's FDA AER row.

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
317
Total Reports
145
Deaths Reported
45.7%
Death-coded share of reports

Active Ingredients

Florfenicol

Administration Routes

UnknownSubcutaneousOralIntramuscularTopicalParenteralOphthalmicNasalOtherIntraocular

Species Affected

Cattle 143
Unknown 73
Fish 34
Human 32
Goat 10
Dog 7
Pig 6
Sheep 6
Cat 4
Alpaca 1

Most Affected Breeds

Unknown 121
Crossbred Bovine/Cattle 39
Cattle (unknown) 26
Holstein-Friesian also known as Holstein 22
Cattle (other) 22
Fish (unknown) 16
Mixed (Cattle) 15
Aberdeen Angus 14
Goat (unknown) 5
Sheep (unknown) 4

Most Reported Reactions

Death 108
Lack of efficacy (bacteria) - NOS 62
Unclassifiable adverse event 42
Accidental exposure 25
Lack of efficacy - NOS 24
Necropsy performed 21
Respiratory tract disorder NOS 18
Death by euthanasia 18
Bronchopneumonia 17
Pneumonia 15
Vials, Leaking 15
Found dead 15

Outcome Breakdown

Died
136 (58.4%)
Outcome Unknown
35 (15.0%)
Recovered/Normal
32 (13.7%)
Euthanized
18 (7.7%)
Ongoing
11 (4.7%)
Recovered with Sequela
1 (0.4%)

Florfenicol: high death-coded share in the FDA AER row

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.

High-volume nationwide drug peers

Two openFDA-derived peer sets for Florfenicol, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

What to do with this drug

A report does not prove a drug caused the reaction; consult a veterinarian before acting on this data.

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

openFDA Animal & Veterinary Adverse Events (FDA CVM) for Florfenicol (#400 of 2,679 by report volume); death-coded 45.7%. PlainBreed drug row · death-coded report count stamp 145 · vintage 2025.

Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →