Drug profile

The FDA adverse-event record for Selemectin

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

#1297 of 2,679
by report volume (all drugs)
38
adverse-event reports
13.2%
death-coded share
Cat
most-reported species
Verify with FDA CVM →

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Selemectin ranks #1283 of 2679 by total reports (38). 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)
#1283
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. Selemectin has 38 reports now versus 38 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 Selemectin changes

Signature read: death-coded share at 13.2% is the most distinctive stamp on Selemectin'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.
38
Total Reports
5
Deaths Reported
13.2%
Death-coded share of reports

Active Ingredients

Selemectin

Administration Routes

TopicalUnknown

Species Affected

Cat 20
Dog 18

Most Affected Breeds

Domestic Shorthair 16
Crossbred Canine/dog 3
Beagle 2
Retriever - Labrador 2
Terrier - Jack Russell 2
Shepherd Dog - German 1
Maine Coon 1
Boxer (German Boxer) 1
Chihuahua 1
Spaniel - Cocker American 1

Most Reported Reactions

INEFFECTIVE, HEARTWORM LARVAE 9
Lethargy (see also Central nervous system depression in 'Neurological') 6
Death 4
Ataxia 4
Vomiting 4
Anorexia 3
Excessive licking and/or grooming 3
Other abnormal test result NOS 3
Elevated serum alkaline phosphatase (SAP) 3
Lack of efficacy (endoparasite) - tapeworm 3
Pruritus 3
Seizure NOS 2

Outcome Breakdown

Outcome Unknown
15 (39.5%)
Ongoing
9 (23.7%)
Recovered/Normal
9 (23.7%)
Died
4 (10.5%)
Euthanized
1 (2.6%)

Selemectin Adverse Event Insights

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 Selemectin (#1297 of 2,679 by report volume); death-coded 13.2%. PlainBreed drug row · death-coded share stamp 13.2% · 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 →