Drug profile

The FDA adverse-event record for Zeranol

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

#680 of 2,679
by report volume (all drugs)
131
adverse-event reports
13.7%
death-coded share
Unknown
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Zeranol ranks #680 of 2679 by total reports (131) and #407 of 1130 by death-coded share (13.7%). 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)
#680
This drug, reports of 2679
#407
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. Zeranol has 131 reports now versus 131 in that prior snapshot: 0 the same number of (0.0%).

Report change
+0
Death-coded reports
+0
Death-coded share
−0.0 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 Zeranol changes

Signature read: death-coded report count at 18 is the most distinctive stamp on Zeranol'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.
131
Total Reports
18
Deaths Reported
13.7%
Death-coded share of reports

Active Ingredients

Zeranol

Administration Routes

UnknownSubcutaneousIntralesionalIntramuscular

Species Affected

Unknown 96
Cattle 30
Human 3
Sheep 1
Horse 1

Most Affected Breeds

Unknown 99
Crossbred Bovine/Cattle 9
Cattle (unknown) 7
Mixed (Cattle) 4
Aberdeen Angus 3
Cattle (other) 3
Holstein-Friesian also known as Holstein 2
Brangus 1
Cattle (unspecified) 1
Crossbred Ovine/sheep 1

Most Reported Reactions

Implant, Abnormal 61
Containers, Abnormal 32
Dispenser, Abnormal 21
Death 16
Anaphylaxis 4
Accidental exposure 4
Underfilling, Package 4
Respiratory tract disorder NOS 4
Dyspnoea 3
Unclassifiable adverse event 3
Injection site pain 3
Collapse (see also 'Cardio-vascular' and 'Systemic disorders') 2

Outcome Breakdown

Died
18 (75.0%)
Outcome Unknown
5 (20.8%)
Recovered/Normal
1 (4.2%)

Zeranol: high report volume 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 Zeranol, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

Similar report volume

Nearest other drugs by FDA report count (131 here).

Similar death-coded share

Nearest other drugs by death-coded share (13.7% here), distinct from the volume row.

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 Zeranol (#680 of 2,679 by report volume); death-coded 13.7%. PlainBreed drug row · death-coded report count stamp 18 · 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 →