Pet Drug Reports

Isoflurane (IsoFlo, Isospire)adverse event reports that FDA received

Active ingredient

Also sold as: IsoFlo, Isospire, Attane, Anirane.

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand.

Read this first. FDA says this about the data:

An API dataset query result cannot be used to estimate the risk associated with the product or compare one drug or device product with another. When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event. This dataset should not be the sole source of information for clinical decision-making or other assumptions about the safety or effectiveness of a product. The adverse event may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources.

FDA Center for Veterinary Medicine publishes these words. Source: Adverse Event Reports for Animal Drugs and Devices, read on . The data have the reports that FDA received through .

This page is not veterinary advice. For an animal that is ill, speak to a veterinarian.

Contacting a veterinarianHow to report to FDA

From July 1990 to June 2026, FDA received 5,260 adverse event reports that name a drug with isoflurane as its active ingredient. Of the 5,260 reports, 2,778 (52.8%) are about dogs. 2,036 reports are about cats (38.7%).

In January to March 2026, FDA received 169 reports that name this drug. The signs that appear in the largest number of the 5,260 reports are "Death", "Lethargy" and "Vomiting". A report is not proof that a drug caused a sign.

Reports that name this drug fell by 7.2% in the 12 months to June 2026, compared with the 12 months before. Reports for all animal drugs fell by 4.6% in the same periods. The newest months can get more reports in a later update. Reports about cats are 38.7% of the reports that name this drug, and 11% of all reports.

Since the last update of the FDA data

The site recorded an update of the FDA data on . FDA changed these counts for January to March 2026:

  • All species: from 139 to 169.
  • Dog: from 62 to 76.
  • Cat: from 75 to 85.
  • Other species or species not given: from 2 to 8.

January to March 2026 is the latest closed quarter in the data. In that quarter FDA received 169 reports that name isoflurane: 76 dog, 85 cat, 0 horse, 8 other or not given.

All updatesFeed of updates (RSS)

Signs that the reports list

A sign is a coded term from the report. The words in brackets are a plain gloss of the term. The percentage is the share of the 5,260 reports that list the sign. One report can list more than one sign.

The sign that is in the largest number of the reports comes first.

  1. Death14.9%784 reports
  2. Lethargy[unusually tired or inactive]11%579 reports
  3. Vomiting8.3%434 reports
  4. Cardiac arrest8%421 reports
  5. Bradycardia[slow heart rate]7.6%400 reports
  6. Ineffective, anesthesia[legacy FDA term: the product did not have the expected effect (anesthesia)]7%366 reports
  7. Anorexia[not eating]6.6%346 reports
  8. Not eating6.3%331 reports
  9. Behavioural disorder NOS[behaviour change, type not specified]5.5%289 reports
  10. Lack of efficacy - NOS[the product did not have the expected effect]5.1%269 reports
  11. Death by euthanasia[the animal was euthanized]4.7%248 reports
  12. Other abnormal test result NOS[abnormal laboratory result, type not specified]4.7%248 reports
  13. Apnoea[breathing stopped]4.6%244 reports
  14. Hypothermia[low body temperature]4.6%241 reports
Show the next 16 signs
  1. Diarrhoea[diarrhea]4.4%232 reports
  2. Fever4%213 reports
  3. Tachycardia[fast heart rate]3.9%204 reports
  4. Ataxia[unsteady, uncoordinated movement]3.9%203 reports
  5. Hypotension[low blood pressure]3.8%201 reports
  6. Vocalisation[crying out or unusual noise]3.6%189 reports
  7. Dilated pupils3.6%187 reports
  8. Recovery prolonged3.4%181 reports
  9. Hyperthermia[raised body temperature]3.4%178 reports
  10. Seizure NOS[seizure, type not specified]3.3%171 reports
  11. Weight loss3.1%162 reports
  12. Elevated alanine aminotransferase (ALT)[a liver enzyme above the normal range]3%160 reports
  13. Dysphoria3%156 reports
  14. Decreased appetite2.9%151 reports
  15. Elevated blood urea nitrogen (BUN)[a kidney value above the normal range]2.9%151 reports
  16. Hyperactivity2.9%151 reports

The list shows 30 of 1,591 coded signs. A report is not proof that a drug caused a sign. Download all signs (CSV)

Reports by species

The share is of all 5,260 reports that name isoflurane. The other reports give a different species or no species.

Reports for each month, Jul 2021 to Jun 2026

Dog1,097 reports. Largest count in one month: 149 (Dec 2024)
Cat1,168 reports. Largest count in one month: 74 (Dec 2024)
Horse34 reports. Largest count in one month: 7 (May 2025)
Other or not given180 reports. Largest count in one month: 10 (May 2023)

The month is the month in which FDA received the report. Each chart has its own scale. FDA says that a report can take 3 to 6 months to reach the public data. The newest months can get more reports in a later update.

Reports by year

  • Dog
  • Cat
  • Horse
  • Other or not given
Reports that name isoflurane, by the year in which FDA received them and by species
YearDogCatHorseOther or not givenAll species
2026131131122285
20252892351746587
2024319293536653
2023139296336474
2022161182626375
202113774327241
202014862021231
201913454114203
201812863012203
201714492011247
20161369618241
20151389928247
20141713008209
20131659409268
20129776014187
2011372202382
2010412731788
20093660244
20082870338
20072464438
2006221201044
20051350119
20041180120
20031450423
2002961521
20011470425
20001180322
19991740627
199811120831
19971540524
19961180221
19951660123
1994530210
199342006
199210001
199110001
199001001

2026 has the reports that FDA received through Jun 2026. Download the years (CSV)

What the reports record

Outcome at the time of the report

  • Recovered/Normal33.7%1,770
  • Recovered with Sequela[recovered, with a lasting effect]0.9%48
  • Ongoing21.3%1,122
  • Died16%842
  • Euthanized4.6%240
  • Outcome Unknown14.7%772

An outcome in a report is not proof that the drug caused it. The person who sends the report gives the outcome. Each share is of the 5,260 reports that name isoflurane.

A report about more than one animal can have more than one outcome.

Kind of report

  • Safety issue90.3%4,751
  • Lack of expected effectiveness2.7%141
  • Both safety and lack of expected effectiveness4%210
  • Manufacturing or product defect2.9%152
  • Other0.1%6

4,385 reports say if the event was serious. 58.6% of them have the serious flag. The person who sends the report sets the flag.

Show age, weight, breed and route

Age of the animal

  • Under 1 year18.8%989
  • 1 to 3 years17%896
  • 4 to 7 years19.9%1,046
  • 8 to 11 years18.6%980
  • 12 years and over9.7%510
  • Age not given16%839

Weight of the animal

  • Under 5 kg (11 lb)30.9%1,626
  • 5 to 9.9 kg (11 to 22 lb)20.7%1,089
  • 10 to 24.9 kg (22 to 55 lb)12.7%666
  • 25 to 44.9 kg (55 to 99 lb)14.1%742
  • 45 kg and over (99 lb and over)2.7%144
  • Weight not given18.9%993

Breed, where the report gives one breed

A breed with many animals has many reports.

Route in the report

  • Respiratory (Inhalation)60%3,158
  • Other0.7%37
  • Endotracheal0.3%17
  • Nasal0.3%17
  • Intravenous0.2%12
  • Oral0.2%8

Each bar is on a scale of 0 to 100%.

Approved animal drugs with this active ingredient (FDA Green Book)

This section is reference data. It has no report count.

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand.

Brand names

  • IsoFlo
  • Isospire
  • Attane
  • Anirane

What the Green Book records give

Applications with an approval in force
6
Approved species
Dogs, Equids, Horses
Dose forms
Liquid
Routes
Inhalation
Sale
RX (prescription)
Earliest approval date in the records

The species, dose forms and routes are the words of the Green Book records for all the applications together. One product can have fewer. The label of a product gives its approved use.

Applications in the Green Book of 2 Nov 2026, pioneer applications (NADA) first
Brand nameActive ingredientsSponsorApproved speciesApplication
IsoFloIsofluraneZoetis Inc.Dogs, HorsesANADA 200-070
IsospireIsofluraneDechra Veterinary Products LLCDogs, HorsesANADA 200-129
AttaneIsofluranePiramal Pharma Ltd.Dogs, HorsesANADA 200-141
Isoflurane, USPIsofluranePiramal Pharma Ltd.Dogs, HorsesANADA 200-237
IsofluraneIsofluraneParnell Technologies Pty. Ltd.Dogs, HorsesANADA 200-821
AniraneIsofluraneBaxter Healthcare Corp.Dogs, HorsesANADA 200-822
Aerraneapproval withdrawnIsofluraneBaxter Healthcare Corp.Dogs, HorsesNADA 135-773

Next in the A to Z list

All drugs by active ingredient. Brand names A to Z

FDA pages for this drug

The site checked these addresses on . The links open in a new tab.

Cite this page

Pet Drug Reports. Isoflurane: adverse event reports that FDA received. https://petdrugreports.com/drug/isoflurane/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of . Reports received through .

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Where the data come from

The counts come from the openFDA Animal and Veterinary adverse event files, export of 30 Oct 2026. The files have the reports that the FDA Center for Veterinary Medicine received through 26 Jun 2026. The files mask brand and manufacturer names. The site counts a drug by the active ingredients that each record gives, and gives no count to a brand, an application or a company. Ingredient names and the lists of approved products follow the FDA Green Book of 2 Nov 2026. The site does not use the application number that a record has.

The site does not publish report text, lot numbers or details of a reporter. FDA's record is the authority. See how the site counts reports, the data sources and the corrections page.

Questions about these reports

Which brand are these reports about?

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand. The Green Book section of this page lists the brand names with this active ingredient.

Do the reports show that the drug caused the signs?

No. FDA states this about the data.

When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event.

The adverse event may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources.

FDA Center for Veterinary Medicine. Source: Adverse Event Reports for Animal Drugs and Devices

How many reports did FDA receive in the latest 12 months?

FDA received 610 reports in the 12 months to June 2026. It received 657 reports in the 12 months before. FDA says that a report can take 3 to 6 months to reach the public data. The newest months can get more reports in a later update.

What kinds of report are in the count?

Of the 5,260 reports received from July 1990 to June 2026, 90.3% are about a safety issue only. 6.7% are about a lack of expected effectiveness, alone or with a safety issue. 2.9% are about a defect of the product or its package.