Drug profile

The FDA adverse-event record for Lotilaner

12,153 FDA reports name Lotilaner, a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#20 of 2,679
by report volume (all drugs)
12,153
adverse-event reports
2.6%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Lotilaner ranks #20 of 2679 by total reports (12,153) and #945 of 1130 by death-coded share (2.6%). 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)
#20
This drug, reports of 2679
#945
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. Lotilaner has 12,153 reports now versus 11,896 in that prior snapshot: 257 more (2.2%).

Report change
+257
Death-coded reports
+9
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 Lotilaner changes

Signature read: 12,153 reports place Lotilaner in the upper third of FDA AER volume (#20 of 2,679).

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
12,153
Total Reports
316
Deaths Reported
2.6%
Death-coded share of reports

Active Ingredients

Lotilaner

Administration Routes

OralUnknownTopicalOtherSubcutaneousAuricular (Otic)OphthalmicCutaneousIntrauterineIntraocular

Species Affected

Dog 10,437
Cat 862
Unknown 828
Human 24
Pig 1
Cattle 1

Most Affected Breeds

Retriever - Labrador 1,272
Unknown 861
Retriever - Golden 769
Dog (unknown) 662
Crossbred Canine/dog 460
Domestic Shorthair 447
Shepherd Dog - Australian 404
Shepherd Dog - German 388
Chihuahua 358
Shih Tzu 313

Most Reported Reactions

Vomiting 2,964
Diarrhoea 1,258
Other abnormal test result NOS 860
Lack of efficacy (ectoparasite) - tick NOS 827
Lack of efficacy (bacteria) - Borrelia 770
UNPALATABLE 725
Lethargy (see also Central nervous system depression in 'Neurological') 702
Seizure NOS 696
Lack of efficacy (ectoparasite) - flea 583
Lack of efficacy (endoparasite) - heartworm 570
Behavioural disorder NOS 531
Lethargy (see also Central nervous system depression in Neurological) 461

Outcome Breakdown

Outcome Unknown
5,126 (45.2%)
Recovered/Normal
3,651 (32.2%)
Ongoing
2,228 (19.7%)
Died
195 (1.7%)
Euthanized
122 (1.1%)
Recovered with Sequela
8 (0.1%)

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

Similar report volume

Nearest other drugs by FDA report count (12,153 here).

Similar death-coded share

Nearest other drugs by death-coded share (2.6% 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 Lotilaner (#20 of 2,679 by report volume); death-coded 2.6%. PlainBreed drug row · report volume stamp 12,153 · 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 →