Reaction profile

The FDA adverse-event record for hypothyroidism

1,092 FDA adverse-event reports reference hypothyroidism (VeDDRA 404). See the species, breeds, and drugs most associated with it below.

1,092
reports citing this reaction
14.9%
death-coded share
Dog
most-affected species
Milbemycin Oxime + Spinosad
most-associated drug
Verify with FDA CVM →
1,092
Total Reports
163
Deaths
14.9%
Death Rate

Species Most Affected

Dog 1,028
Cat 61
Human 2
Horse 1

Breeds Most Affected

Retriever - Labrador 123
Crossbred Canine/dog 103
Retriever - Golden 53
Boxer (German Boxer) 44
Domestic Shorthair 43
Chihuahua 35
Maltese 26
Spitz - German Pomeranian 26
Terrier - Yorkshire 24
Beagle 23

Associated Drugs

Milbemycin Oxime + Spinosad 199
Trilostane 139
Carprofen 77
Oclacitinib Maleate 68
Spinosad 59
Fluralaner Chew Tablets 55
Afoxolaner 49
Bedinvetmab 47
Fluralaner 13.64% 12-Week Chew 40
Milbemycin Oxime + Praziquantel 38
Levothyroxine 34
Prednisone 32
Imidacloprid + Moxidectin 31
Deracoxib 28
Cyclosporine 26
Gabapentin 26
Moxidectin 25
Milbemycin Oxime 25
Thiamazole 24
Ivermectin + Pyrantel As Pamoate Salt 24

Hypothyroidism Reaction Insights

1,092 reports name Hypothyroidism; 163 recorded a death outcome (14.9% of reported events, not a population-level mortality rate). VeDDRA code: 404.

By species: Dog (1,028 reports), Cat (61 reports), Human (2 reports). By breed: Retriever - Labrador (123), Crossbred Canine/dog (103), Retriever - Golden (53).

Most co-reported drugs: Milbemycin Oxime + Spinosad (199 reports), Trilostane (139 reports), Carprofen (77 reports), Oclacitinib Maleate (68 reports).

Read these counts as reporting volume, not risk: per our methodology, co-reporting reflects temporal association captured in voluntary submissions, not proof that a drug caused this reaction. A widely-prescribed drug will rack up more raw co-reports at an identical true rate than a rarely-used one, so compare within similar-exposure products.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.