Reaction profile

The FDA adverse-event record for hypothyroidism

1,137 FDA reports name hypothyroidism, a high-volume reaction in the CVM extract (VeDDRA 404). Plate stamps and neighbourhood peers follow.

#352 of 2,481
by report volume (all reactions)
1,137
reports citing this reaction
15.0%
death-coded share
Dog
most-affected species

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. Hypothyroidism has 1,137 reports now versus 1,120 in that prior snapshot: 17 more (1.5%).

Report change
+17
Death-coded reports
+1
Death-coded share
−0.1 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 Hypothyroidism changes

FDA AER · VeDDRA plate

Code 404 VOL-MID

VOL-MID · DEATH-ELEV · UPPER-Q · PHOTO-FINISH · SPECIES-DOG · DRUG-LEAD · DESK-WIDE · BOOK-FULL

  • VOL-MID 1,137 reports
  • DEATH-ELEV 15.0%
  • UPPER-Q #352/2481
  • PHOTO-FINISH Regurgitation
  • SPECIES-DOG Dog · 1,066
  • DRUG-LEAD Milbemycin Oxime… · 201
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Regurgitation (±1 reports)

Upper-third report volume drives the scale stamps on this plate; death-coded share and co-report peers follow. Not a clinical diagnosis.

High-volume neighbourhood around Hypothyroidism

Upper-third volume poles plus nearest peers, not a full reaction corpus board reprint.

Vomiting · highest174348Cardiac enlargement · near1140Hypothyroidism · this reacti…1137Regurgitation · near1136Tubes, Damaged · near1136Low sodium-potassium… · near1134Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Hypothyroidism

What the FDA AER plate says about Hypothyroidism

Signature read: 170 death-coded reports is a heavy tail count for Hypothyroidism in the CVM extract. Report volume is upper-third scale: 1,137 named reports in the openFDA extract. 170 of 1,137 reports were death-coded (15.0% of named reports, not a population mortality rate). Nearest volume peer: Regurgitation (±1 reports). Lead species Dog (1,066). Lead co-reported drug Milbemycin Oxime + Spinosad (201).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Milbemycin Oxime + Spinosad appears in filings alongside this reaction; that is association, not causation. Browse the full reactions index or the about page for how PlainBreed frames FDA CVM extracts.

Species Most Affected

Dog 1,066
Cat 68
Human 2
Horse 1

Breeds Most Affected

Retriever - Labrador 127
Crossbred Canine/dog 104
Retriever - Golden 53
Boxer (German Boxer) 48
Domestic Shorthair 47
Chihuahua 35
Maltese 27
Spitz - German Pomeranian 27
Beagle 25
Shepherd Dog - German 24

Associated Drugs

Milbemycin Oxime + Spinosad 201
Trilostane 152
Carprofen 82
Oclacitinib Maleate 75
Spinosad 59
Fluralaner Chew Tablets 55
Bedinvetmab 52
Afoxolaner 49
Fluralaner 13.64% 12-Week Chew 44
Milbemycin Oxime + Praziquantel 39
Levothyroxine 38
Prednisone 34
Gabapentin 34
Imidacloprid + Moxidectin 32
Maropitant Citrate 31
Deracoxib 28
Cyclosporine 26
Moxidectin 25
Milbemycin Oxime 25
Thiamazole 24

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Hypothyroidism, both floored at ≥50 reports so the neighborhoods stay in the advertised mass (the volume chart above is the unfloored photo-finish strip).

Similar death-coded share

Nearest other reactions by death-coded share (15.0% here), distinct from the volume row.

What to do with this reaction

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 Hypothyroidism (#352 of 2,481 by report volume); death-coded 15.0%. PlainBreed reaction plate · death-coded report count stamp 170 · 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 →