Reaction profile

The FDA adverse-event record for unequal pupils

90 FDA adverse-event reports reference unequal pupils (VeDDRA 671). See the species, breeds, and drugs most associated with it below.

90
reports citing this reaction
11.1%
death-coded share
Cat
most-affected species
Florfenicol + Mometasone Furoate + Terbinafine Hydrochloride
most-associated drug
Verify with FDA CVM →
90
Total Reports
10
Deaths
11.1%
Death Rate

Species Most Affected

Cat 48
Dog 41
Horse 1

Breeds Most Affected

Domestic Shorthair 34
Shepherd Dog - Australian 6
Siberian Husky 4
Spitz - German Pomeranian 3
Shepherd Dog - German 3
Domestic Mediumhair 3
Retriever - Labrador 2
Chihuahua 2
Siamese 2
Domestic Longhair 2

Associated Drugs

Florfenicol + Mometasone Furoate + Terbinafine Hydrochloride 13
Milbemycin Oxime + Spinosad 7
Isoflurane 7
Cefovecin 6
Robenacoxib 5
Afoxolaner 5
Cefovecin Sodium 5
Maropitant Citrate 4
Cyclosporine 4
Buprenorphine 4
Ear Cleaner (Unknown) 4
Pyrantel Pamoate;Sarolaner 4
Methylprednisolone Acetate 3
Selamectin 3
Insulin Injectable Vial 3
Nitenpyram 3
Lotilaner 3
Florfenicol, Terbinafine, Betamethasone Acetate 3
Moxidectin 2
Betamethasone + Florfenicol + Terbinafine 2

Unequal pupils Reaction Insights

90 reports name Unequal pupils; 10 recorded a death outcome (11.1% of reported events, not a population-level mortality rate). VeDDRA code: 671.

By species: Cat (48 reports), Dog (41 reports), Horse (1 reports). By breed: Domestic Shorthair (34), Shepherd Dog - Australian (6), Siberian Husky (4).

Most co-reported drugs: Florfenicol + Mometasone Furoate + Terbinafine Hydrochloride (13 reports), Milbemycin Oxime + Spinosad (7 reports), Isoflurane (7 reports), Cefovecin (6 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.