Drug profile

The FDA adverse-event record for Phenobarbitol

58 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Phenobarbitol. See the species affected, top reactions, and outcomes below.

58
adverse-event reports
24.1%
death-coded share
Dog
most-reported species
24
Seizure NOS - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
58
Total Reports
14
Deaths Reported
24.1%
Death Rate

Active Ingredients

Phenobarbitol

Administration Routes

OralUnknownIntravenousTopicalOphthalmic

Species Affected

Dog 57
Cat 1

Most Affected Breeds

Crossbred Canine/dog 8
Retriever - Labrador 5
Chihuahua 4
Dachshund (unspecified) 4
Retriever - Golden 4
Terrier - Yorkshire 3
Shih Tzu 3
Bulldog - French 2
Bichon Frise 2
Mixed (Dog) 1

Most Reported Reactions

Seizure NOS 24
Death by euthanasia 9
Ataxia 5
Lethargy (see also Central nervous system depression in 'Neurological') 5
Death 5
Unable to stand 4
Behavioural disorder NOS 4
Restlessness 3
Weakness 3
Diarrhoea 3
Elevated gamma-glutamyl transferase (GGT) 3
Paddling 3

Outcome Breakdown

Outcome Unknown
19 (32.8%)
Recovered/Normal
17 (29.3%)
Euthanized
9 (15.5%)
Ongoing
7 (12.1%)
Died
5 (8.6%)
Recovered with Sequela
1 (1.7%)

Phenobarbitol Adverse Event Insights

58 reports name Phenobarbitol; 14 recorded a death outcome (24.1% of reported events, not a population-level mortality rate). Active ingredient: Phenobarbitol. Administration routes: Oral, Unknown, Intravenous, Topical.

By species: Dog (57 reports), Cat (1 reports). By breed: Crossbred Canine/dog (8), Retriever - Labrador (5), Chihuahua (4).

Leading clinical signs: Seizure NOS (24), Death by euthanasia (9), Ataxia (5), Lethargy (see also Central nervous system depression in 'Neurological') (5). Outcome, 58 coded reports: Outcome Unknown leads at 32.8%.

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.

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.