Drug profile

The FDA adverse-event record for Isoflurane

4,251 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Isoflurane. See the species affected, top reactions, and outcomes below.

4,251
adverse-event reports
18.7%
death-coded share
Dog
most-reported species
558
Death - 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.
4,251
Total Reports
794
Deaths Reported
18.7%
Death Rate

Active Ingredients

Isoflurane

Administration Routes

Respiratory (Inhalation)UnknownOtherIntravenousNasalEndotrachealTopicalOralParenteralOphthalmic

Species Affected

Dog 2,226
Cat 1,693
Human 69
Unknown 58
Other 46
Rabbit 36
Horse 35
Mouse 16
Guinea Pig 11
Other Birds 10

Most Affected Breeds

Domestic Shorthair 968
Unknown 300
Retriever - Labrador 260
Dog (unknown) 208
Cat (unknown) 196
Domestic Longhair 130
Chihuahua 97
Crossbred Canine/dog 88
Retriever - Golden 82
Domestic Mediumhair 72

Most Reported Reactions

Death 558
Vomiting 372
Bradycardia 333
Lethargy (see also Central nervous system depression in 'Neurological') 331
Anorexia 306
Cardiac arrest 304
Not eating 262
INEFFECTIVE, ANESTHESIA 248
Behavioural disorder NOS 248
Lack of efficacy - NOS 225
Other abnormal test result NOS 217
Hypothermia 210

Outcome Breakdown

Recovered/Normal
1,571 (38.7%)
Ongoing
979 (24.1%)
Outcome Unknown
667 (16.4%)
Died
604 (14.9%)
Euthanized
197 (4.8%)
Recovered with Sequela
45 (1.1%)

Isoflurane Adverse Event Insights

4,251 reports name Isoflurane; 794 recorded a death outcome (18.7% of reported events, not a population-level mortality rate). Active ingredient: Isoflurane. Administration routes: Respiratory (Inhalation), Unknown, Other, Intravenous.

By species: Dog (2,226 reports), Cat (1,693 reports), Human (69 reports). By breed: Domestic Shorthair (968), Unknown (300), Retriever - Labrador (260).

Leading clinical signs: Death (558), Vomiting (372), Bradycardia (333), Lethargy (see also Central nervous system depression in 'Neurological') (331). Outcome, 4,063 coded reports: Recovered/Normal leads at 38.7%.

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.