Drug profile

The FDA adverse-event record for Levamisole

21 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Levamisole. Species, reactions, and outcomes follow.

#1757 of 2,679
by report volume (all drugs)
21
adverse-event reports
57.1%
death-coded share
Sheep
most-reported species
Verify with FDA CVM →

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Levamisole ranks #1727 of 2679 by total reports (21). Death-coded-share rank requires at least 50 reports. 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)
#1727
This drug, reports of 2679

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. Levamisole has 21 reports now versus 21 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 Levamisole changes

Signature read: Levamisole's 57.1% death-coded share is among the highest in the openFDA drug corpus.

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
21
Total Reports
12
Deaths Reported
57.1%
Death-coded share of reports

Active Ingredients

Levamisole

Administration Routes

OralUnknown

Species Affected

Sheep 8
Goat 4
Horse 2
Dog 2
Unknown 2
Cat 2
Human 1

Most Affected Breeds

Sheep (unknown) 6
Unknown 4
Goat (unknown) 2
Domestic Shorthair 2
Crossbred Equine/horse 1
Thoroughbred 1
Nubian 1
Southdown 1
Bulldog - French 1
Crossbred Ovine/sheep 1

Most Reported Reactions

Death 8
Ataxia 4
Overdose 4
Neurological symptoms NOS 3
Neurological signs NOS 2
Dermatitis 2
Death by euthanasia 2
Staggering 2
Behavioural disorder NOS 2
Twitching 2
Collapse NOS (see also 'Cardio-vascular' and 'Neurological disorders') 2
Vestibular disorder NOS 2

Outcome Breakdown

Died
10 (45.5%)
Outcome Unknown
4 (18.2%)
Recovered/Normal
3 (13.6%)
Ongoing
3 (13.6%)
Euthanized
2 (9.1%)

Levamisole: 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.

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 Levamisole (#1757 of 2,679 by report volume); death-coded 57.1%. PlainBreed drug row · death-coded share stamp 57.1% · 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 →