Drug profile

The FDA adverse-event record for Estriol

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

#242 of 2,679
by report volume (all drugs)
679
adverse-event reports
7.5%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Estriol ranks #242 of 2679 by total reports (679) and #669 of 1130 by death-coded share (7.5%). 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)
#242
This drug, reports of 2679
#669
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. Estriol has 679 reports now versus 664 in that prior snapshot: 15 more (2.3%).

Report change
+15
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 Estriol changes

Signature read: 679 reports place Estriol in the upper third of FDA AER volume (#242 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.
679
Total Reports
51
Deaths Reported
7.5%
Death-coded share of reports

Active Ingredients

Estriol

Administration Routes

OralUnknown

Species Affected

Dog 678
Rat 1

Most Affected Breeds

Crossbred Canine/dog 108
Retriever - Labrador 75
Shepherd Dog - German 33
Doberman Pinscher 32
Dog (unknown) 24
Boxer (German Boxer) 20
Siberian Husky 16
Poodle (unspecified) 15
Schnauzer (unspecified) 13
Pit Bull 13

Most Reported Reactions

Lack of efficacy - NOS 263
Vaginal swelling 82
Vomiting 62
Anorexia 46
Death by euthanasia 41
Diarrhoea 40
Urinary tract infection 32
Polydipsia 23
Weight loss 23
Seizure NOS 23
Decreased appetite 21
Lethargy (see also Central nervous system depression in Neurological) 21

Outcome Breakdown

Ongoing
108 (35.3%)
Recovered/Normal
81 (26.5%)
Outcome Unknown
65 (21.2%)
Died
31 (10.1%)
Euthanized
20 (6.5%)
Recovered with Sequela
1 (0.3%)

Estriol: high report volume 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 Estriol, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

Similar report volume

Nearest other drugs by FDA report count (679 here).

Similar death-coded share

Nearest other drugs by death-coded share (7.5% 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 Estriol (#242 of 2,679 by report volume); death-coded 7.5%. PlainBreed drug row · report volume stamp 679 · 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 →