Drug profile

The FDA adverse-event record for Frontline

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

#1356 of 2,679
by report volume (all drugs)
34
adverse-event reports
2.9%
death-coded share
Dog
most-reported species
Verify with FDA CVM →

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Frontline ranks #1344 of 2679 by total reports (34). 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)
#1344
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. Frontline has 34 reports now versus 34 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 Frontline changes

Signature read: Frontline's 2.9% death-coded share is among the lowest 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.
34
Total Reports
1
Deaths Reported
2.9%
Death-coded share of reports

Active Ingredients

Frontline

Administration Routes

TopicalUnknown

Species Affected

Dog 27
Cat 7

Most Affected Breeds

Retriever - Labrador 6
Domestic Shorthair 4
Domestic Longhair 2
Crossbred Canine/dog 2
Siberian Husky 2
Doberman Pinscher 2
Terrier (unspecified) 2
Spaniel - Cocker American 1
Chihuahua 1
Spitz - American Eskimo Dog 1

Most Reported Reactions

Lack of efficacy (bacteria) - Borrelia 8
Lack of efficacy (bacteria) - NOS 4
Vomiting 3
Lethargy (see also Central nervous system depression in 'Neurological') 3
Lethargy (see also Central nervous system depression in Neurological) 3
Diarrhoea 2
Anorexia 2
Weight loss 2
Lack of efficacy (ectoparasite) - tick NOS 2
Hot spot (pyotraumatic dermatitis) 2
Application site alopecia 1
Anaemia NOS 1

Outcome Breakdown

Ongoing
21 (61.8%)
Outcome Unknown
8 (23.5%)
Recovered with Sequela
2 (5.9%)
Recovered/Normal
2 (5.9%)
Euthanized
1 (2.9%)

Frontline: 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.

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 Frontline (#1356 of 2,679 by report volume); death-coded 2.9%. PlainBreed drug row · death-coded share stamp 2.9% · 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 →