Drug profile

The FDA adverse-event record for Amprolium

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

#514 of 2,679
by report volume (all drugs)
225
adverse-event reports
16.9%
death-coded share
Unknown
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Amprolium ranks #514 of 2679 by total reports (225) and #310 of 1130 by death-coded share (16.9%). 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)
#514
This drug, reports of 2679
#310
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. Amprolium has 225 reports now versus 223 in that prior snapshot: 2 more (0.9%).

Report change
+2
Death-coded reports
+0
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 Amprolium changes

Signature read: death-coded report count at 38 is the most distinctive stamp on Amprolium'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.
225
Total Reports
38
Deaths Reported
16.9%
Death-coded share of reports

Active Ingredients

Amprolium

Administration Routes

UnknownOralTopicalRespiratory (Inhalation)

Species Affected

Unknown 120
Cattle 55
Human 21
Chicken 6
Goat 5
Sheep 5
Dog 4
Horse 4
Turkey 3
Rabbit 1

Most Affected Breeds

Unknown 141
Holstein-Friesian also known as Holstein 13
Cattle (unknown) 13
Aberdeen Angus 9
Cattle (other) 9
Mixed (Cattle) 6
Chicken (unknown) 5
Goat (unknown) 4
Sheep (unknown) 3
Turkey (unknown) 3

Most Reported Reactions

Appearance, Abnormal 73
Contamination, Particulate Matter 34
Death 29
Lack of efficacy (protozoa) - Coccidia 25
Potency, Low 18
Unclassifiable adverse event 15
Accidental exposure 15
Diarrhoea 13
Product defect NOS 10
Bloody diarrhoea 9
Lack of efficacy - NOS 9
Uncoded sign 9

Outcome Breakdown

Died
38 (44.7%)
Outcome Unknown
22 (25.9%)
Recovered/Normal
13 (15.3%)
Ongoing
7 (8.2%)
Euthanized
5 (5.9%)

Amprolium: 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 Amprolium, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

Similar death-coded share

Nearest other drugs by death-coded share (16.9% 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 Amprolium (#514 of 2,679 by report volume); death-coded 16.9%. PlainBreed drug row · death-coded report count stamp 38 · 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 →