Reaction profile

The FDA adverse-event record for ineffective, seizures

51 FDA adverse-event reports reference ineffective, seizures (VeDDRA 99146). See the species, breeds, and drugs most associated with it below.

51
reports citing this reaction
9.8%
death-coded share
Dog
most-affected species
Phenobarbital
most-associated drug
Verify with FDA CVM →
51
Total Reports
5
Deaths
9.8%
Death Rate

Species Most Affected

Dog 43
Cat 7
Horse 1

Breeds Most Affected

Dog (unknown) 17
Crossbred Canine/dog 6
Cat (unknown) 6
Terrier - Yorkshire 2
Boxer (German Boxer) 2
Terrier - Boston 1
Domestic (unspecified) 1
Terrier - Scottish 1
Schipperke 1
Poodle (unspecified) 1

Associated Drugs

Phenobarbital 24
Potassium Bromide 23
Levetiracetam 9
Zonisamide 7
Levothyroxine 2
Spinosad 1
Glucosamine 1
Glycosaminoglycan Polysulfate 1
Midazolam Hcl 1
Benazepril 1
Pimobendan 1
S-Adenosylmethionine/Silybin-Phosphatidylcholine Complex 1
Polysulfated Glycosaminoglycan 1
Glucosamine Hydrochloride Supplement 1
Methimazole 1
Topiramate 1
Midazolam 1
Diazepam 1

INEFFECTIVE, SEIZURES Reaction Insights

51 reports name INEFFECTIVE, SEIZURES; 5 recorded a death outcome (9.8% of reported events, not a population-level mortality rate). VeDDRA code: 99146.

By species: Dog (43 reports), Cat (7 reports), Horse (1 reports). By breed: Dog (unknown) (17), Crossbred Canine/dog (6), Cat (unknown) (6).

Most co-reported drugs: Phenobarbital (24 reports), Potassium Bromide (23 reports), Levetiracetam (9 reports), Zonisamide (7 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.