Isoflurane

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4,251 adverse event reports submitted to the FDA

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
1870.0%
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%)

Data Summary

Metric Value
Total adverse event reports 4,251
Reports involving death 794
Case-fatality rate (reported events) 1870.0%
Distinct species in reports 10
Distinct breeds in reports 20
Distinct reactions reported 20
Active ingredients on file 1

Source: FDA Center for Veterinary Medicine — Adverse Event Reporting (CVM AER). Counts reflect voluntary reports only.

Isoflurane Adverse Event Insights

The FDA Center for Veterinary Medicine database currently holds 4,251 adverse event reports referencing Isoflurane, including 794 reports in which the animal died — a 1870.0% case-fatality figure among reported events only, not a population-level mortality rate. Active ingredient on file: Isoflurane. Reported administration routes include Respiratory (Inhalation), Unknown, Other, Intravenous. These numbers reflect voluntary submissions from pet owners, veterinarians, and manufacturers and therefore under-represent mild events and over-represent severe ones — a pattern the FDA has documented repeatedly for pharmacovigilance datasets.

The species most frequently named in Isoflurane reports are Dog (2,226 reports), Cat (1,693 reports), Human (69 reports), with Dog accounting for the largest share. Within those species, Domestic Shorthair (968), Unknown (300), Retriever - Labrador (260) appear most often — though breed popularity and ownership density shape these counts as much as any drug-specific sensitivity. This distribution matters because the same active ingredient can behave very differently across body sizes, ages, and species physiology.

The most commonly reported clinical signs associated with Isoflurane are Death (558), Vomiting (372), Bradycardia (333), Lethargy (see also Central nervous system depression in 'Neurological') (331). Of the 4,063 reports with a coded outcome, Recovered/Normal is the leading category at 38.7%. Because FDA adverse event data describes correlation rather than causation, these figures are best used to frame informed questions with a veterinarian and to compare reporting patterns across related products — not as a standalone safety verdict on Isoflurane.

Source: FDA Center for Veterinary Medicine — Adverse Event Reports FDA Center for Veterinary Medicine — Adverse Event Reports Data reflects voluntary submissions and may not represent actual incidence rates

Related

Data sourced from official AKC, AVMA, ACVO, and breed-club veterinary references. See our methodology for details. Retrieved and formatted by PlainBreed Editorial